Dia Portable (Visio) Dia is roughly inspired by the commercial Windows program Visio, though more geared towards informal diagrams for casual use.
FileZilla Portable (FTP) FTP in your pocket
FileZilla Portable is the popular FTP client package
Audacity Portable A simple audio editor and recorder
VLC Media Player Portable Aeasy to use media player that plays many formats
Foxit Reader Portable (Freeware) small and fast PDF reader
without the 100 meg download
KeePass
Password Safe Portable Secure, easy-to-use password
manager
Fast, Friendly, Free
These are just a few of the free and extreamely useful apps available at portableapps.com. They are fast, stable and lightweight. Put them on a 'Sandisk' memory stick and take them with you. For most users, they have all the power of installed apps without the bloat.