Oh, man. When my pal, Gretchen, and I start our bakery-slash-detective agency, I'm SO getting one of these. Maybe a dozen.
Slip this Camera Pen into your pocket and snap pictures or videos discreetly by just tapping the top. You can record up to 2 hours of video with audio or take nice, clean 2 megapixel images. It even has a motion sensor so you can record when you are not present. Built-rechargeable lithium-ion battery and built-in 4GB of memory (2.0 USB key) included.
International Center of Photography - Camera Pen
(Thanks, Nate! This is brilliant.)