By osfameron from Italia.pm,London.pm,NorthWestEngland.pm,Edinburgh.pm
Learning Haskell is an, er, interesting experience for a Perl programmer.
Purely functional programming is an eye opener: allegedly it will make you a better programmer, but first of all, there is a good chance that it will make you cry.
Things like IO, random numbers, and even state need you to understand things called Monads... eeek!
Obviously this makes the ideal project to learn Haskell an implementation of the classic Unix game of luck and skill: Dope Wars!