I'm playing Warmachine tonight. Hopefully afterwards, I can coax some of the players to try out "Captcha". I really want to change the name... The best I could come up with is "Scramble!" It's close enough to Scrabble and you are doing just that, scrambling for tiles. I took a picture of the prototype that I wanted to add to this post but I didn't have time before I left for work. Hopefully, I'll have a photo up soon as well as the results of the playtest.
Edit: No dice tonight. No one wanted to stick around, but I do have a picture from last night.