Hang on, did he just buy essentially a freely reprogrammable FPGA with built-in RAM, A/D converter and USB support - for $20? Seems to me, you could do a lot more with those devices, now that the wire protocol is known.
(Edit) It doesn't appear that he decoded the bitstream format though, so some more work would be needed before you could use it as a general-purpose FPGA.
(Edit) It doesn't appear that he decoded the bitstream format though, so some more work would be needed before you could use it as a general-purpose FPGA.