Lets share some cool free apps. here is a list of a few that i like/use. Lets try not to suggest games or applications that are well known.
RocketDock
It's like the dock in Mac OSX but for windows
http://rocketdock.com/
Mesh
a beta made by microsoft, it lets you share files and do remote desktop.
https://www.mesh.com/welcome/default.aspx
Free Natural Reader
a text to speech program. IT's good for when you are trying to do more then one thing at a time.
http://www.naturalreaders.com/
CamStudio
Maybe this one is to well known but anyway. It's a screen capture program.
http://camstudio.org/
PortableApps
lets you run some apps form you thumbdrive
http://portableapps.com/
7Zip
a nice easy to use zip and 7Z converter. I think it can do a few other file types as well.
http://www.7-zip.org/
Blender
this one is also fairly well known. it's a very complex, but full feathered 3D modeling program.
http://www.blender.org/
