Sandboxie (Security)

It' s a small program that can isolate others programs from the rest of your pc.

So you can safely run any suspicious program without fearing that your computer will be messed up.

You can even run you favorite browser through sandboxie and navigate to those underground sites that have usefull "info" but also put tons of trojans on your drive.

Site: http://www.sandboxie.com/
License: Freeware / Shareware