Have you tried a Lens Baby? - More from PMA
The Lens Baby is not a new device, but it does keep getting better.
The Lens Baby allows you to create a sharp area in your image with a stylishly soft vignette that is completly adjustable. These effects can be done in photoshop, but there is something satisfying about getting the result in camera. The later model allows you to lock the setting in. These are much more than a toy.
As for it's popularity, you should note that a Lens Baby was used extensively in the filming of the Oscar® nominated film "The Diving Bell and the Butterfly". I want one! Cheers, Paul