Mobility Email

Mobility Email is a portable distribution of the Mozilla Thunderbird email client that can be used from a USB key.
It includes OpenPGP signing and encryption, extensions for accessing Hotmail, Yahoo!, Lycos and MailDotCom, and good documentation.

Download IdeaTiger Extension (source) package
Download IdeaTiger Extension (zipfile) package
Download Mobility IM (zipfile) package
Download Mobility Mail Install Packages package for WIN
Download Mobility Mail Packages package for WIN
Download Themes package
Get more detail at http://mobility.sourceforge.net/