Having been rumored leading upto WWDC 2013, Apple has officially announced that AirDrop wireless sharing will indeed be coming to iOS devices with iOS 7. The big caveat is that due to hardware requirements, it will only be available on iPhone 5, iPod touch 5th generation, iPad mini and iPad 4.
AirDrop on iOS works much the same as on OS X -- in that users nearby that have AirDrop will show up on your device, and you can send items such as photos to them with a simple tap. The other device taps to accept and the file transfers. Pretty neat.