While looking around the Facebook developers docs I’ve found a page called Programming Puzzles. Basicaly if you want to work for Facebook you better try to solve some of these puzzles with one or more of the suggested languages and send the source code along with your resume.
Next week after my university final exams I’ll try to solve some of them in Erlang and Ruby, in the meantime have a look and try yourself. 
Annuncio con immenso piacere che sul numero di Giugno di Computer Programming potete trovare il primo dei miei tre articoli su Erlang. In questo numero ho trattato principalmente la parte sintattica del linguaggio, facendo qualche esempio e introducendo il lettore alla programmazione funzionale. Correte in edicola!
Translation for all the non-italian readers: in the June issue of Computer Programming, the leading italian programming magazine, you can find the first of three articles I wrote about Erlang. It’s a great introduction to the language, so if you have an italian friend who wants to know more about this language, tell him to buy the magazine! 
Yesterday I’ve been at the PHPDay 2007 in Verona with my Nimboo friend Giovanni Intini, during the travel to Verona on the train, we played with Erlang, Ruby and PHP writing small programs to compute Pythagorean triplets and comparing performances.
I don’t want to tell you yet who’s the winner, you will find the results of our tests in Giovanni’s blog.
Update: the battle continues here.
After seeing the Peter Norvig’s implementation of a Spell corrector in 20 lines of python code, I would like to add an Erlang implementation to the perl6 one made by Gabriele.
Unfortunately I’m blocked by an issue I’m still trying to solve. (update: thanks to your suggestions I’ve solved the “folding” issue)
Here’s what I did until now:
