Like others I'm bothered when buildings seem to lean. I think some of this is caused by lens distortion. The attached photo was taken with an A100 with a wide angle zoom set to 18mm. The first of the following imaged is the JPG as produced by the camera un-touched by PP. A second photo was made from the RAW and shows some cropping and "free transform", shadow fixer, etc done in PP. I'm not sure if I corrected for lens distortion or introduced distortion of my own. I welcome your comments. Notice how the woman sitting on the bench has her left distorted.