[Tom Bottiglieri]

I agree, doing the processing with a local coprocessor is the way to go. You need to have additional electronics no matter what to deal with pulling the data, so why not spend a bit more and throw a whole Linux at it?

There are a bunch of low cost ARM based boards out there that can act as USB hosts. The panda board, beagle board, and beagle bone are all TI OMAP (TI's mobile device system on chip offering) dev boards. I assume they have enough horsepower to do the necessary CV on the depth maps, but I wouldn't use it without doing a bit more research.