On my 10D with a 20mm lens. It's not that small of a sensor Honestly, I was tempted to distort the angles more in Photoshop, but then I thought it worked well as it was.
In Photoshop, duplicate your layer and gaussian blur the new one by 30-40 (assumes 6 megapixel image. If your image is smaller or larger, adjust the blur amount). Then, select "overlay" as the blending mode for the layer. Adjust opacity to suit. You can also add a layer mask to erase the effect for areas that need to be sharp. This technique works well for portraits too: Zachary.