Adam over at Lifehacker has a problem. His wife locks up all his porn on a Windows machine that only she knows the password to. That's why Adam came up with a guide to easily crack a Windows password using the Ophcrack Live CD.
It's extremely simple. All you have to do is stick in the CD, pick the account you want to crack, and it'll start churning away. Useful if you have to break into a departed co-worker/wife/child/lover's machine. Or your own machine if you're an idiot and forget your password.
p.s. I made up that story about Adam. He keeps his porn on his own machine.