I’m not sure why I haven’t run across this in the past, but I just saw an AVR demo board called the AVR Butterfly. It has an LCD, joystick, speaker, temperature sensor, a real-time clock, voltage sensor, and serial port all for an amazing $20 over at Mouser or DigiKey. The whole package is about the size of a name tag and runs on a single button battery.
The Butterfly looks like a prime candidate for a cheap prototype platform (it has an ATmega169V Microcontroller) and diagnostic probe. Not only that, people have been using it for other projects. There’s a low power logger project called Butterfly Logger. Another project called Buttload uses a Butterfly as an ISP Programmer. So, instead of spending $22 for LadyAda’s USBtinyISP, you can give Buttload a shot since it can be modified to program over USB too.
I need to order one of these soon since I’m itching to mess with it.