Portable software

PortableApps.com is a good place you can look to for portable software to take with you on your USB.
You best bet is to grab the PortableApps.com Suite™ a complete collection of portable apps including a web browser, email client, office suite, calendar/scheduler, instant messaging client, antivirus, audio player, sudoku game, password manager, PDF reader, minesweeper clone, backup utility and integrated menu, all preconfigured to work portably.
Just drop it on your portable device and you're ready to go.

http://portableapps.com/