Burn Bootloader on Arduino Mega

I think I have corrupted my Bootloader on my Arduino Mega 1280 board. I just got a usbtiny programmer and was messing around with it and I believe I messed up the bootloader:( For now, I cannot down load sketches via usb using the Arduino IDE version 22. So what is the command line magic incantantion to load the default Bootloader using avrdude with a usbtiny programmer, so I can de-brickify my Arduino?

You can burn the bootloader for a mega1280 using a USBtiny directly from the Arduino IDE. Just select the mega1280 board in the tools menu and then the Burn Bootloader selection from the same menu.


I tried that and the burn failed. So I was hoping to do it directly from avrdude. Anyone have the command line for that?