Perplexcity

NOT - This ARG (Alternate Reality Game) is simple in concept. The Receda Cube has been stolen out of Perplex city and is somewhere here on earth. You only have to find it and earn $200,000 (real money). The great thing about this game is how to get clues. You can visit dedicated sites (newspapers, blogs) to solve the puzzles and get clues.

Someone has even use SETI-like programs to solve some puzzles; you can download the client here. And the hunt for clues even goes on in the real world. On eBay you can buy Perplex City cards with which you can solve the mystery. So if you have interesting clues, post them also here. When I win the $200k, I'll let you know!