bokeh_heart.jpg
Before:
bokeh_regular.jpg
After:
bokeh_hearts.jpg

I haven’t tried this, so I hope I’m not being hoodwinked. This article on DIYPhotography shows how to cut out a sort of lens gobo to shape high contrast parts of an out-of-focus photograph.
Bonus points for the first person to build a “MAKE:” bokeh one letter at a time and post the results on the MAKE Flickr pool!
Speaking of which, this example came from the MAKE Flickr pool:

bokeh_inMyHeart.jpg

via Digg