Even though you spend a lot of money on a lens, every lens has some inherent flaws, but this video tutorial with Robbie Carman and Richard Harrington demonstrates that these distortions can be fixed in an unexpected way.
Photoshop Extended CS5 allows you to open video clips and convert to a smart object, which allows you to run a filter on entire video clip instead of just one frame. Menu options within Photoshop allow you to choose your camera and lens, and if your lens is not available yet, create profiles online at Adobe for your own specific lenses and cameras, then watch Photoshop Extended begin correcting lens distortion.