LEGO Batman: DC Super Heroes is now available for the iPhone, iPad, and iPod Touch devices. The game offers both a classic or use the new touch screen specific control scheme. You can also unlock characters the normal way or just throw cash at it to unlock characters right away.
LEGO Batman actually looks pretty great running on the iOS based on some of the gameplay footage I was able to find on YouTube. Definitely appears to be worth the $4.99 asking price.