Guangzhou Darling DP2000
Projector type:640x480, 9 lumens
The DP2000 is a WinCE running pico projector from Guangzhou Darling in China. It includes a mouse-pad to control the OS, a USB host (to connect an external keyboard or mouse), speakers, and 1Gb internal memory (and a microSD card slot).
The price is 180$, and they claim 4-hours battery life.