Are you up for a little contest? Check out this site: http://www.try2hack.nl/level1.html
If you can defeat the password, you'll get to the next level. The first levels are easy, but soon you'll have your hand full!
You will need a text editor and a few decompilers. (And a little bit of knowledge....) Pretty fun!
Myself, I've just got to level 4. Anyone better?