Many new computers over the past few years come with a minimum of six USB ports (four in the back and two up front). With cameras, scanners, printers, MP3 players, external hard drives, mice, keyboards and more, what seemed like a lot of ports quickly dwindles. You could add an external USB hub that plugs into one of your ports then gives you four more, for a net gain of three. Hubs can be found for about $20-30. More often, however, I'm recommending people spend less than $10 and get a PCI USB expansion card that gives you a net gain of four or more USB ports.
Installing a USB card is extremely easy and requires no software for Windows 2000 or Windows XP machines. Just shut your computer off, open the side of the case (make sure you are grounded), take out a PCI space cover, insert the new USB card (and screw if your computer needs it), close up the case, turn on the PC and that's it! For half the price of a hub, an extra net port and NO extra clutter on your desk, you can't beat the convenience. One of the best places to buy a hub is online at Newegg.com. Their prices and speed can't be beat.