Solving problems in Project Euler

I've been working on my programming skills lately(been learning Python 3.1!!) and I just stumbled upon Project Euler. Project Euler is a series of computer problems, which are mostly mathematical in nature(and quite tricky too!!). As of now, the website has 300+ problems which you can solve(in any order). You don't have to actually post the program though, you just have to submit the answer.

Project Euler is not really a contest- you don't win anything(it's just about giving yourself an ego boost). The problems are basically targeted to mathematics and computer enthusiasts who want to challenge themselves and have fun.

Solving problems on Project Euler,as I've found out, can become quite addictive, although quite mind-stretching. Anyone who's interested in programming and mathematics will find Project Euler to be very fun. Best of luck for solving the problems!!