At work I've been told to do a project based on the Neuros OSD. Suddenly I became very interested on this project and (as in the case of the GP2X) was interested on kernel stuff and the EFL. I started a project to port the Neuros' closed source drivers into open ones. I've coded several drivers already like the framebuffer (one of the most important beside the DSP), I2C, serial, etc. Check the project page if you are interested on this.