Synergy is Free and Open Source Software that lets you easily share your mouse and keyboard between multiple computers, where each computer has it's own display. No special hardware is required, all you need is a local area network. Synergy is supported on Windows, Mac OS X and Linux.
JSkype is an JNI implementation which enables Java clients to use the Skyp API. - windows only :(
PlayOnLinux (POL) is a python-based frontend (with bash install scripts) to install windows programs in Wine. Si tu ne peux pas te passer de crtains programmes de windows... voici peut-être une solution
Download music from LastFM, MySpace, etc...
The Google Map Image Cutter is an application designed to take any image or digital photo and cut it into tiles which are displayed on a Google Map. Using this tool, large images can be published on the web in a format that allows the user to pan and zoom
OGLE (i.e. OpenGLExtractor) is an open source software package that allows for the capture and re-use of 3D geometry data from 3D graphics applications running on Microsoft Windows.