Haskell is

the white man's burden of programming languages.

>>120
Try these:

https://prof.ti.bfh.ch/hew1/informatik3/prolog/p-99/   <-- Ninety-nine Prolog Problems
http://www.pythonchallenge.com/
http://projecteuler.net/      
http://www.programming-challenges.com/
http://www.topcoder.com
http://www.spoj.pl   <- Sphere Online Judge

The List monad will be especially useful for the first one.