Here's interesting Android + Arduino project that was linked from the Make blog:
http://blog.makezine.com/2012/02/02/displaying-phone-video-on-an-rgb-led-matrix/
I used the OpenCV library to convert the video frames to 16×32 pixel resolution to match the LED matrix. I also constrained the color space of the frames to 12 bit color. That is, each pixel has 4 bits each for red, green, and blue. That means that each pixel can have 16 different brightness levels of red/green/blue, yielding 4096 possible colors. In other words, all of the image processing is performed on the phone because it’s much more powerful than the Arduino.
Anyone here working on an Arduino & Android project?
Cheers,
Drew


