I'd think that most of the major PP programs have a perspective correction tool.
I use Paint Shop Photo Pro X2, and from what I've seen, it's tool for this is pretty standard.
Here's your original, a screenshot of the perspective tool -- I moved the corner points of the tool to make the sides of the trapezoid roughly parallel to the leaning buildings -- and the corrected version. Took about 10 seconds. This is just a quick and dirty illustration, and I think that it might have stretched the center building too much, but that could have been helped by moving the top of the trapezoid down a bit.