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,...