Russell Brown is the Sr. Creative Director at Adobe Systems and a great innovator in the use of Photoshop. Until I discovered his new video above I wasn't even aware that Photoshop CS6 had the capability of adaptively correcting lens distortion. I frequently shoot various wide angle lenses and have long been a devotee of panoramas, but this will take future creations to an entirely new level.
Have a look at what Dr. Brown has done here, and if you have CS6 be sure and give the new Adaptive Wide Angle filter a try. This video is sure to help you learn how to process images with this amazing filter correctly!