Funkloader
funkloader is a RFM12-based bootloader application targetted at the Atmel AVR ATmega8. In theory it should work for other devices but since it heavily relies on assembler code, especially regarding the startup code, this probably requires quite some adjustments.
The main design goal is to keep it short, this is always at most 512 bytes long.
If you're interested, have a look at http://git.brokenpipe.de/cgi-bin/gitweb.cgi?p=bricolage/funkloader
You can clone the repository using
git clone git://git.brokenpipe.de/bricolage/funkloader
There's a similar (derived) project by Christian Dietrich, who does bootloading over his ZBus protocol. Have a look ZBus for details.