Blizzard Europe ran a contest during Gamescom, where fans could take their picture with the Diablo street art display in the Rudolfplatz, style it up a bit, and post it on some form of social media. The three best entries were promised a spot in the Diablo III beta, and today Bliz EU posted the winners. You can see them below, and all three are pretty clever and deserving, I think.
Thanks to Mikael for the news tip.