How can i simply un-distort an image with "crooked buildings" ?

[hypercat]

What is the simplest way, in PDN, to un-distort a photographic image that has distorted perspective (such as with "crooked buildings", etc) ?  Is there a photo app that includes such a "Perspective Correction" tool ?  Many years ago i had a (now defunct) Corel app that had it (one simply clicked on corner points of a distorted object in the image, then the next click would instantly bring those points (and the rest of the image) to proper perspective.

[BoltBait]

Try this plugin:

 

 

[Red ochre]

I find this a simple way to correct whole photos before applying other distortions.

Camera lens distortion correction

 

(kindly found by E.E.R)