Take your most important apps around on a USB stick. Most of these are available from http://portableapps.com. Here are the ones I use.
- OpenOffice -- Office Suite and line-art design tools
- FireZilla -- FTP
- Nvu -- Web page editor
- Firefox -- Web browser
- LockNote -- Encrypt a text file (to store passwords, etc.)
- PSPad -- Text Editor
- PStart -- App Launcher
- Gimp -- Image editor
- MySQL-Front -- MySQL database tool. I use the old, open-source version; there is a newer commercial version here. A good server-side alternative is phpMyAdmin.
Additional portable apps, including games, can be found here.