I put my first Erlang program in a pastebin. It's a concurrent prime sieve. Likely not the most efficient way to do things, but I'm still all pleased with myself. :-)
I may or may not choose to program more sophisticated things in Erlang, but I figured a passing familiarity was in order. Especially since I'm thinking of using CouchDB for something and it's written in Erlang. While knowing Erlang isn't necessary to understand CouchDB, I figure that it certainly can't hurt.