The $1.19 app gives you an almost unlimited playground to create virtual Lego masterpieces. It includes dozens of brick types in dozens of colours, so you're only restricted by your imagination. There are nine different backgrounds you can work on, and you can easily share your creation with a built-in screenshot function.
Lego in an iPhone app. It's a win-win situation, especially for the $1.19 price tag.
[iTunes - Thanks Wade!]