Here's something fun: it's an Arduino Uno doing ISP on itself!

The 8U2 USB chip is running modified software - essentially the standard USBserial code, merged with a heavily modified version of the ArduinoISP sketch. The nice thing is that it can switch between normal operation and ISP just by adding or removing a jumper.
If anybody is interested in trying out this code, let me know and I'll tidy it up and write some instructions. You'll need an Uno R2 (R1 will
not work; R3 is probably ok but I don't have one to test) and either an ISP programmer or another Arduino. Some soldering is required (to add the extra header pins). You'll also need to be fairly confident about reprogramming the 8U2 - as always with ISP, there's potential for bricking the device if anything goes wrong.

