Kotaku - I earned this commendation yesterday after playing the Nintendo 3DS' built-in role-playing game, Find Mii.
Let's unpack this a bit, shall we?
Nintendo, which isn't big on Xbox-like Achievements, does have an Achievement-like system built into the 3DS.
The 3DS' achievements primarily reward users for networking their system to others'. You get commendations when your 3DS wirelessly connects to a bunch of other 3DSes that are registered to people from other countries. You get them for "meeting" the same person('s 3DS) a bunch of times in a row. Stuff like that. You also get accomplishments recognized for feats in the system's Find Mii game.