I recently discovered the portable apps website. This site provides a selection of open source server and client applications that can run directly from a USB stick. The Apps include:

• Apache Web server
• MySQL database server
• FileZilla ftp server
• Firefox browser
• Open Office
• Gimp

As the apps are portable, they execute directly from the USB stick and do not require installing on the host machine. Plugin the USB stick on a loaned machine or portable and all your opensource tools are available FireFox with plugins, gimp, word processor, spreadsheet and presentation software - instant web server, ftp server, database server, etc.

Recently I had to transfer files from a server to a laptop that wasn't part of the domain. Plugin the USB stick into the laptop, fire up the ftp server, add a user with password and map the drive, ftp from the server and transfer the file - BOSH, BOSH, job done. Close down the ftp server and remove the stick.