For years, getting onto the Internet meant plugging into it—that is, literally connecting a wire to your computer that, if you could crawl inside and follow it through all the walls, ceilings, pipes, and relay stations of the world, would eventually lead you to the Internet.
Nowadays, however, an increasing number of people get online without connecting any wires at all. Wireless hot spots, also known as WiFi or AirPort networks, are invisible pools of Internet signal, 300 feet across, that let wireless-equipped computers get onto the Internet at high speed. Travelers with wireless-ready laptops connect to the Internet via these wireless hot spots in airports, coffee shops, hotel lobbies, and just about anywhere else they have work to do or time to kill.
Usually, you have to pay a fee to use one of these public hot spots. But if you live in an apartment building or other tightly spaced housing, an even better option may await you. You may be able to hop onto the Internet using someone else's wireless signal. Sometimes the signal bleeds into your home without the owner's knowledge, in which case—you very lucky person—you may be able to get online free, at least until the owner catches on. More often, though, someone in the building makes his signal available deliberately, collecting, say, $5 a month from each person who shares it.
If you're such a lucky neighbor, then it's not true that you need an ISP to get onto the Internet. Your neighbor has an ISP account, which he's sharing with you. In that case, you're getting online not via an ISP, but through a VSN—a Very Shrewd Neighbor.
But WiFi networks are also very useful at home. If your cable modem or DSL box is in an inconvenient area of the house, and you don't feel like snaking 50 feet of ugly network cable from the den to the bedroom, setting up a wireless network to share your broadband connection is just the ticket.
Setting up a wireless hot spot in your home is easy, at least compared with other networking tasks. Remember how you'd ordinarily connect your cable modem or DSL box directly to your computer? For a wireless network, you connect it instead to a $40 box called a wireless router, which then beams the network signal over radio waves to the entire house (or at least to the nearest 150 feet of it, even through walls). Any computer with wireless networking circuitry can join this type of network; in fact, they can all surf simultaneously.
Most laptops sold these days have a built-in wireless card inside, but you can easily add one to an older laptop. Wireless network adapters are also available in different forms for desktop computers as well. Home Networking: The Missing Manual covers creating and configuring a wireless network in detail.
When you first turn on your wireless laptop in the vicinity of a wireless network—whether at home or in some public place—Windows XP and Mac OS X usually bring it to your attention. A dialog box asks if you want to join it. (Figure 1-12 shows this situation in Windows.)
Figure 1-12. Top: You're wandering with your WiFi laptop. Suddenly, fortune smiles: this systemtray balloon appears. You've found a hot spot! You click the balloon. Second from top: You get to read about the network you've found. To get online, click the network's name and then click Connect. (This message is warning you that hackers with network-sniffing software could, in theory, intercept your wireless transmissions—always a concern with public wireless networks.) If a yellow padlock appears, you can't use the network without a password. Third from top: In your Network Places window, getting Properties on a wireless connection produces this box. By rearranging the networks' names, you tell Windows which ones you want to connect to first, in the delightful event that more than one hot spot is available at once. Bottom: The next time you wander into a hot spot you've connected to before, XP connects automatically—no muss, no dialog boxes.
If the hot spot, like those in airports and hotels, requires payment up front, clicking OK or Connect doesn't actually get you onto the real Internet. Instead, you're now supposed to open your Web browser, where you'll find a demand for your credit card number. Prices vary, but $8 for 24 hours worth of access isn't unusual. You can't proceed to the wider Web or check your email until you first plug in a credit card number and sign up for a plan (that is, you pay for 15 minutes, an hour, or a day of service).
Public networks are not private places. It's theoretically possible for a hacker seated nearby, using special packet sniffing software, to intercept text that you're sending by email or writing in a chat room. (Transactions on Web pages, however, are safe as long as you see a tiny padlock icon in the corner of the Web browser window.) Chapter 21 has plenty of information on how to keep yourself safe online at home and in the hotspot.