nuxie1.com – Hackaday Competition Entry… he beat me to it. I laid out and etched my own boards to do precisely what he’s done here… however, since it looks like he’s already gone through the trouble of testing and revising his board, I’m just going to use his. Nice work!
Also, his website had an interesting ad linking to www.hobbylab.us/USBOscilloscope/Home.htm, which looks like a pretty interesting oscope. I wonder if there’s a linux tool like that. Note that it does 1KHz to 1MHz, but it also does i2c, uart, 1wire and spi. That could be very useful.