About time I post something here... :)
I have been experimenting with an alternative use for LEDs. What most people don't know is, that part from emitting light, LEDs can be used as light detectors. To try this, use a picaxe 28x1 or other picaxe that has ports that can be used as both output and input. I have connected a standard green LED (the detector) with anode to port c1 and cathode to port c0 with no resistor on either pins. Also, I have a stanard red LED (indicator) with a 330ohm resistor on the standard output port 0 and GND.