What about re-designing the BeagleBone Black into a functional mobile phone considering it's open-hardware and similair to OMAP(am3559). It's amazing how many OS's can be run. Adding peripherals wouldn't be that difficult as there's the great amount of I/O pins that can be used.

I have one and must say this is the only board that is fully open-source both hardware and software. The PCB design etc. are all hosted by Texas Instruments.