Lensbaby has a pretty good track record in making lenses that allow you to take photos with all manner of wacky focus effects. Now it's targeting the budget end of the market with the Spark, a $US80 lens that turns your DSLR into a selective-focus shooter.
Capable of attaching to a Canon or Nikon, this 50mm lens features a fixed f/5.6 aperture and focuses from 13 inches to infinity. All you do is squeeze the unit to focus and tilt it on its axis to move the "sweet spot" on the fly. The result should be images packed with the kind of focus effects you normally use Photoshop to achieve.