Home WiFi Networks
Wi-Fi is short for "Wireless Fidelity," and it is the popular name for 802.11-based technologies. Ten to twenty years ago, everyone used modems to dial into a server (wow, remember when you first got a 2400-baud modem and thought you were fast. Compared to the early birds with their 300-baud modems, you were). Then,in the late 80’s, early 90’s, Ethernet started showing up in offices – these are the wires that look like phone cords except the wires are a little thicker and the plugs are a little bigger. They are also much faster – phone modems are pretty much limited to 56000 bits per second while the initial Ethernet was 10 million, 100 million is common today and 1000 million equipment is available.
In fairly recent time (ca. 1999), the wireless protocols were proposed and in the last couple of years WiFi has become very common in offices and homes as a way to tie multiple computers together (i.e. network them) without needing to run wires to each computer. They are a little slower than Ethernet, but still much faster than phone connections. Concurrently with people setting these up in their homes and offices, some companies have started putting commercially available 'hotspots' - locations in airports, hotels and coffee shops (T-mobile® at Starbucks, for example) where you can receive and send signals so you can get connected on the road (of course, many of these places charge you for the privilege of using their connection).
In technical terms, WiFi has certain similarities to cordless phones (not wireless that you can use virtually anywhere, but cordless/portable that have a base station which plugs into your wall socket and a handset that you can use around your home). In fact, WiFi and cordless phones even use some of the same radio frequencies. Unlike cordless phones that have a matched pair of handset/base station, WiFi has much more flexibility. The ‘base station’ (called an access point or AP) can connect to multiple ‘handsets’ (WiFi equipped computers) or you can just connect computers to each other.
What range can you expect? I'm afraid there is no easy answer to that because it depends on more factors than the card itself. The standards and manufacturer's spec sheets suggest a range up to 500 feet (~150 meters) but this is in optimum conditions with no walls or other obstructions. However, with a good card and a good access point (AP)/router, you should have coverage throughout your home. The more walls/floors between your PPC and the AP, the shorter the distance will be. If you can design your network so the AP is located near the center of the range you want to cover, you'll have better success.
In my real life example, I have an SMC CF card and a Belkin AP located in my basement near the center of the house. I get full (100%) signal strength everywhere in the house and I can go anywhere in my back yard and ~150 ft down the street in front before the signal starts to drop.
So, if you want to free your PPC from the USB cable, and still be able to use it to connect to the Internet or send and receive email, WiFi may be your way to go.
If you still have questions, check the WiFi Frequently Asked Questions.