If you're looking for a puzzle game with a humanitarian cause (and I never thought I'd say that!) then you might find Foldit worth checking out. Foldit claims to be a 'revolutionary new computer game' that enables you to contribute to important scientific research while solving a series of biological puzzles. The aim is to help the scientists behind it understand the function of proteins and amino acids. If it sounds a bit weird then bear with me, because it does work, apparently.
Foldit requires you to solve increasingly complex protein chain puzzles with the help of a Dr. David Baker. As you solve the connection puzzles, you earn points, which help you rise up the online rankings, so you're effectively competing with players across the Net.
How does this help further medical science I hear you say? The performance of different competitors helps scientists to discover whether humans' pattern-recognition and puzzle-solving abilities make them more efficient than existing computer programs at pattern-folding tasks. The theory is, if this is the case, human strategies can be taught to computers to fold proteins faster than ever and thus speed-up research into life threating illnesses.
So what of the game itself? You have to use the cursor to manipulate a chain of amino acids anywhere along it. The aim to fold the protein into its optimum shape. The only rules are based on physics which means that opposite attract, you can rotate all bonds as easily as others and generally, the molecule isn't as easy to manipulate as it should be. However, the closer you get to the optimum shape, the more points you score.
It has to be said that Foldit isn't the most engaging game you'll ever play but the fact that it's doing some real good for medical research means you're doing more than just kill a few minutes of time.