Instead of lugging a laptop on your next trip, save your aching back by taking your computer's desktop with you on a thumb drive or iPod. Portable Windows software offerings such as MojoPac and U3 put a full desktop on your USB thumb drive (or on your disk-use-enabled iPod), letting you run applications such as Microsoft Outlook and save documents on that drive. All you need is a host PC: You can plug the MOjoPac drive into your in-laws' system or a coffee-shop workstation, for instance, to access your documents and applications without leaving a trace behind Alternatively, you can save and run free portable applications-such as the Firefox browser, Pidgin 1M client, and Sumatra PDF reader-from your thumb drive. Download those and other programs for free at Portable.