Many of the photos we take have perspective problems, but there are not too many utilities for iOS the deal with it. The iPhone has a fairly wide angle lens, and as a result, pictures of city buildings, landscapes with lots of trees, almost anything with vertical lines can need some perspective correction.
Perspective Correct (U.S. $1.99) is a new app that deals with just this problem. You import a photo and then by swiping across the screen you can change vertical or horizontal distortion. After that's corrected, you'll need to crop the photo and the app includes a built-in cropping tool. There is also a tool to make a white or black background around the image.
You can also get perspective problems wi