It's not available for purchase yet, but the tiny Microvision Pico projector on display at Macworld Expo definitely made an impact. The device -- roughly the size and weight of an iPhone -- throws a clear and sharp WVGA (848x480) image across a table or a room onto any light-colored surface.
With VGA and composite video inputs, it's a perfect match for portable media players of any sort, or road-warrior presentation needs for small audiences. Battery power is slated to last about 2 hours (90 minutes on the prototype) and it charges over USB. A laser-based projection technology creates images that never need focusing, regardless of the throw distance.
Microvision expects to ship the Pico device in the middle of 2009, with pricing not yet finalized ("at or under $500" is the expectation). We got a little bit of hands-on time in the video below. Note that the scan pattern visible when the projection is in frame is an artifact of the camera's scan rate -- the actual projected image looks great. You can also see some fascinating "unofficial" experiments using a Pico projector at the underground Pico blog.