C-Sky: A $6 Linux dev board with HDMI and USB
No networking it looks like.<p>Whenever I see these dev boards (and I have dozens), I'm always tempted to just use a cell phone.<p>Does your project need networking?  A battery?  A display?  Bluetooth?  Try cobbling together an arduino like solution and you'll spend > $50.  You can buy a smartphone with wifi and touchscreen running android for $10.