usbprog - USB programmer for Atmel AVR controllers (with avrdude support and online update service)
usbprog is a simple and small USB programming adapter that supports nearly all Atmel micro controllers (ATiny,ATMega,AT89,...). You can easy update the usbprog firmware with the same USB connection, which you need to programm other controllers, and a internet connection. So the adapter should be attractive for a long time, because nearly everything around the project is open source and therefore new controllers can be integrated simply.
Complete open source!