http://www.heidi.ie/eraser/
Eraser is another good one, if you have "sensitive" info on your PC, when you delete something it doesnt actually remove it from your hard drive until something is written over it, so the data (Pr0n) can still be accessed by law enforcement, or whoever else knows how to find it. Eraser will write 0s over the free space, up to 32 passes. I believe 7 is the standard used by the Government, so it basically destroys all the crap you have deleted.