iPhoneAssassin is a meshing of a social game and iPhone geekyness.  The site says: iPhone Assassin is a game for iPhone users where you virtually "assassinate" other iPhone users.
To play, first sign up by pressing JOIN at the main page at iPhoneAssassin.com. This will give you your special code name, consisting of three letters and a number, such as "Alpha Bravo Charlie 1" or "ABC1".
Next, click on the "Set your nickname" link to create a nickname, like "Joe the Assassin".
Now, go and find someone else with an iPhone. Show them your iPhone and tell them "This is an iPhone Assassination!" Then, tell them to use the iPhone Safari browser to go to iPhoneAssassin.com so they can join the game.

I have to admit I only 'assassinated' people in my office and they looked rather confused...but I still think this is a good idea. 

Poke the smileys and make them go away...another game from myHip that's just like many others from them.  Not the most amazing game but if you're bored and want to waste 5 minutes this works. 

There are a lot of higher quality games out there though. 

This is pretty much Bejeweled without the razzle dazzle. Match the colors and get rid of the rows. 

You'll start out with two colors making the first level very easy but as the levels go on it becomes more difficult.  Overall, I like the simplicity of Avalanche.  It's easy to understand and play.

The game says: Tap the balls before they disappear! For level 1, blast 20 balls to advance to level 2. Each level requires more balls to advance to the next level. See if you can complete all 10 levels! 

Trust me, it really does get more difficult as the levels move along.