Browsing through the search for second life images I accidentally stumbled upon Perplex City. For those of you who like puzzles and mysteries then this is for YOU!!! Described on the website as "A city obsessed with puzzles and ciphers. A game that blurs the boundaries between fiction and reality. Begin an incredible, immersive adventure that spills out into the real world. Interrogate suspects over the phone, search police files for evidence, decipher coded emails and check newspapers for clues - working with tens of thousands of players around the world." The first season of the game actually gave away 100,000 British Pounds to the winner. Unfortunately the second season is on hold until further notice.
Link - Perplex City