If you want to bring a projector in your pocket (or your bag) for use with your iPod or iPhone, than this Lancerlink iJector, an LCOS projector. Shaped like a dock, the device makes it possible to watch video stored on your iPod on the go via its built-on stereo speakers (3W×2ch).

Casio announced at InfoComm the release of  a new Super Slim DLP projector model featuring WXGA (1280 x 800) native resolution, bringing widescreen presentations to your business or home.  The XJ-S43W comes equipped with an HDMI input (High Defninition Multimedia Interface)
It has an output brightness of 2,500 ANSI lumen and has 2x power zoom lens.
The XJ-S43W enables short distances of 2.8 feet and can reach a total of 30 feet. Casio’s projector measures only 1.26 inch at its thinnest point with an overall thickness of 1.69 inch.
And it costs …