standalone programmer

[Nantonos]

You could take my bootloader uploader:

Just put it into a plastic box, provide power, and run the ICSP cable out a hole. That uploads a single bootloader kept in its memory, and does the fuses.

In its current form you command it to write the bootloader with serial comms, but you could have it test a button and do it. And have an LED or two to show when it is programming and when it is done.

Nick, would your bootloader uploader also be suitable for uploading alternative 8U2 code to a USB controoler chip via it's ICSP header? Or does the Arduino used as a programmer need to be the same architecture and running the same program as will be uploaded to the target device?