It's certainly not comprehensive, but here's the shortlist of stuff I make to try out a new language, in order of increasing complexity: -- Sudoku verifier --

It's certainly not comprehensive, but here's the shortlist of stuff I make to try out a new language, in order of increasing complexity: -- Sudoku verifier -- library generator (scan all of the music files on your drive and compile a list of artists) -- dictionary app (using Wordnik API) -- flexible calculator that can detect postfix v. prefix -- Sudoku solver -- Hidato solver (which is essentially King's tour, but cooler) -- tumblr API wrapper (or really any OAuth service) -- n-gram language classifier