Okay, so it's not directly Arduino related (I'm only using an Arduino Diecimilla for its 5V regulated power here :-) ) but I thought I'd share this:
It's a programming "jig" I created for use with a parallel cable programmer I had access to--I used a circuit schematic I found online but worked out the protoboard layout and did the soldering all by myself--so I'm kinda proud of that. :-) Worked first time too! :D
More details can be found on my page for learning about the AVR parallel programmer and constructing a programming jig.
I'm planning to use the programmer and jig to burn the bootloader onto bare ATMegas.