Ten years ago, only propellerheads would consider installing a home network. Nowadays, a combination of cheap hardware and network-ready operating systems has made the prospect a lot more mainstream. And there are many compelling reasons for doing it.

When networked, every computer in the home can share a printer--so you can cost-justify getting a really good one. And it's possible to share a single Internet connection too--assuming your broadband provider permits it (or doesn't find out). And for the real gadget freak, it's now becoming possible to integrate your computer network to home automation gadgetry--so that from a Web browser at work, you can adjust your home thermostat, turn on the porch light, and even survey the property using cheap PC cams.

The first step, of course, is to figure out how to connect all your computers. There are three basic methods--a wired Ethernet connection, a wireless 802.11b connection (commonly known as Wi-Fi), and a HomePlug Powerline network that uses your home's AC power wires to communicate between computers. You can also use phone lines to carry an inaudible network signal--using technology standards from the Home Phoneline Networking Alliance, but we won't be looking too closely at this method here--it requires rewiring in most houses, and if you're doing that, you might as well go with the faster Ethernet connection.

The Classic Network: CAT-5 Ethernet

Pros: The classic computer network, Ethernet, affords the fastest connection speeds--at least six times faster than a standard broadband Internet connection. Wired Ethernet is the most time-tested method of all, since it's been used in offices for years. All the hardware is available cheaply from many suppliers.

Cons: In most home settings, it requires dragging CAT-5 cable through your wall cavities and screwing Ethernet access points into walls. For laptops, it's sometimes fiddly to hook up an extra wire.

Products required: NIC: All the wires in an Ethernet network need to plug into an Ethernet network interface card (NIC)--usually built into the motherboard or in an add-on card in the computer. On notebooks, a $40 or cheaper PC Card adds Ethernet networking support. Computers with USB ports can use a $30 USB-based Ethernet adapter from Belkin Components, Linksys, Microsoft, and other sources.

Router: To handle traffic among all the computers and other devices on an Ethernet network, you also need a multiport router to plug Ethernet cables into. Ideally, you should have one that connects directly to a broadband modem, so that every computer can share access to the Internet without needing a PC on all the time to handle the connection sharing. There is no shortage of models that can do this--in fact, some broadband modems have built-in routers--but some of the models we've tested include Linksys EtherFast Cable/DSL Router, D-Link DI-604, and Microsoft's Wired Base Station MN-100. These models also have built-in firewalls for added security.

Hub: If you have up to four items to network in one room, a $30 hub lets you share a single Ethernet access point.

In the air: Wi-Fi networking

Pros: A network using the wireless standard 802.11b requires no rewiring. Many vendors make the products, and wireless-enabled notebooks can be used away from the home in offices, and to access the Internet in airports and coffee shops (for a subscription fee). The range varies depending on architecture, but unless you have metal studs in your walls, it can span several stories and into the garden.

Cons: Network communications get slower the further you get from the access point. Setup gets complicated if you add encrypted security--and you should because open wireless access points can be hacked by any passerby with an Orinoco card in his laptop.

Products required: Wireless access point: A wireless access point for about $130 from Linksys, NetGear, Microsoft and others enables you to broadcast and receive network communications through the air. Like routers, these work best if they plug directly into a broadband modem, so you can share Internet access without PCs. The better ones, like Microsoft's Wireless Base Station and Dell's TrueMobile 1184 Wireless Broadband Router, also provide several CAT-5 sockets for wired Ethernet routing too.

Wireless PC Card: A few notebooks are beginning to appear with built-in wireless adapters, but most require a $40-$70 PC Card from such luminaries as Orinoco, Intel, Motorola, and the ever-present Microsoft.

Wireless adapter for desktops: For desktop computers, you can either buy and install an add-in card onto your motherboard or plug in a $70 external adapter. Networking hardware companies like Linksys provide Ethernet wireless bridge products; Dell recently introduced the TrueMobile 1180 Wireless USB adapter that plugs into USB 1.2 or 2.0 ports for PCs that lack Ethernet ports.

Plug and play: Powerline networks

Pros: HomePlug powerline networks are a tad faster than wireless networks, and plug into regular Ethernet hardware such as NICs and routers. They have a range of about 100 feet of electrical wire, and are harder to hack than wireless networks.

Cons: At about the same prices as wireless, powerline networks aren't a compelling buy for notebook users--especially those who already have an Orinoco card for their office wireless network.

Products required: HomePlug PowerLine adapter: A slew of members of the HomePlug Powerline Alliance produce boxes (see HomePlug's Web site for a list of vendors). Adapters plug directly into power outlets at one end and use CAT-5 Ethernet cables to plug into regular Ethernet ports on computers, broadband routers, and other network devices. Their role is to fake out Ethernet hardware that it's plugged into a regular CAT-5-based network--albeit one that operates at just under 10Mbps.

PowerLine to wireless bridges: Coming late into the game are hybrid networking boxes that sit between wireless and powerline networks. Two of the usual suspects in the HomePlug world--Asoka USA Corp and Siemens' Efficient Networks--have recently introduced devices that plug into power sockets and create wireless access points. The $100 Siemens SpeedStream Powerline 802.11b Wireless Access Point and $200 Asoka PlugLink PL Wireless Access Point enhance dead zones in wireless networks using powerlines--or enable you to use your notebook from work on a powerline network.

Networked entertainment

Networks let you share all the expected computer hardware--the files and services like printers attached to PCs and Macs. More importantly, they let you share broadband Internet connections for high-speed, always-on Internet access. But there's a burgeoning group of gadget freaks who are using networks to hook up their home entertainment centers to computers both in the home and on the Net.

For a couple of years, Internet radios have been kicking around on the fringes of the audiophile market. Component stereo devices like Turtle Beach Systems' $300 AudioTron AT-101 digital audio receiver plug into tuners and CD decks at one end and Ethernet networks at the other. It finds the computer on the network and automatically scans its shared music directories for digital music in MP3, WMA, and WAV formats--then plays them back. The AudioTron can also stream music from SHOUTcast and Icecast Internet radio stations, using a fairly simple setup from the company's TurtleRadio site, where you can set up a favorite set of Internet radio stations. The AudioTron uses 24-bit digital-to-analog converters, which deliver smooth and clean playback through your home stereo components. A device like this is a natural addition to a wired Ethernet or HomePlug Powerline network.

Also for around the $300 mark are two more recent Ethernet-enabled audio devices--Onkyo's NC-500, a component like Turtle Beach's AudioTron, and an all-in-one boombox from Philips called Streamium MC-i200. This features an AM/FM tuner and a CD player that can play back CD-Rs full of MP3 tracks--but its real draw is the Ethernet connection that receives Internet radio and plays back MP3s from any of your networked PCs.

For those with a wireless home network, another stereo component worth watching is Motorola's Simplefi. This deck delivers the same kind of features as the AudioTron and NC-500, but handles its networking through Wi-Fi.

Bridging the gap to home automation

Although home LANS are making inroads into the living room through your stereo deck, it's not quite as easy to hook them up to more ambitious home controls such as your thermostat, lights, and coffee makers. This is the dream Microsoft was peddling when it introduced Universal Plug and Play support in Windows XP--the idea that you could control your home's UPnP refrigerator from your office using just a Web browser. That particular vision is a long way off, at least it is by using UPnP products.

The major home automation systems--IBM's HomeDirector and X10 ActiveHome--use computerless adapters controlled by TV-style hand-held remotes to work their magic. Compared to computer networks, home automation systems are fairly basic. You plug adapters into power sockets or light-bulb sockets and plug your devices into the adapter. The adapter controls the flow of electricity to your device, that is, turning them on or off. They get their instructions through the power lines, and can store these instructions to perform particular tasks at given times. Some specialized home automation adapters, such as thermostats and dimmer switches for lights, can handle more complicated controls.

But although the primary interface with home automation systems is the remote control, computer users can get in on the act. X10 provides a serial adapter and several Windows programs to program home automation devices. The programs essentially translate PC instructions into X10 signals because computers and home automation devices are not mutually compatible. X10's Windows-based ActiveHome software, for example, can schedule groups of activities (such as turning on the porch light, oven, and radio) at specific times. Better yet, it can vary the schedule based on your region's sunrise and sunset times. A starter kit including this software, one adapter, and various remote controls, sells for about $50. For about the same price, X10 also sells the more robust FireCracker software and adapter, which can control up to 256 devices in an X10 system.

For very specific tasks like surveillance, other remote access options exist. Regular Web cams such as Logitech's QuickCam come with software to upload images to a Web site either at regular intervals or when they detect motion. If the bundled software lacks such a feature, a $30 download called CoffeeCup WebCam will do it.

This doesn't really allow you to perform tasks from remote locations, however. To do this, you need to add a workaround. The best bet is to keep a computer hooked up to the Internet and running a remote control package such as pcAnywhere or GoToMyPC. To perform remote control of an automated home, you'd tap into your home computer running X10 software and reprogram everything remotely. A nuisance, it's true, but it works.

The holy grail of remote home automation, Web-based remote control, is still around the corner. The Association for Home Appliance Manufacturers (AHAM) and its smart appliance task force reckon that it will be several years before you see production models of, say, washers and driers that send you e-mail when they're done with their cycle.

But for more than a year, chip maker Zilog has been quietly selling developer kits that bridge the gap between the Internet and X10 networks. The company's eZ80 Acclaim! family of developer products hook up to a home broadband router via Ethernet and act as Web servers that control all manner of home automation products. The kits are being bought by hobbyists and product developers alike (pretty much the same market that was installing home wireless networks a few years ago), spending $600 for a full kit or as little as $100 for various modules.

According to Mike Gershowitz, Zilog's director of microcontroller product marketing, it will be a year before the developer's kit evolves into a series of retail products, but by the 2004 holiday season, a variety of manufacturers should be cranking out Internet-enabled home automation products for consumers.

So in a couple of years, you'll be able to program your sprinkler system and turn on your air conditioning from a Web browser at your office (or the airport, or the coffee shop)--all without needing a pocket protector or propeller beanie.