I'm looking to put a bootloader in a Mega168 that will talk over rs232 or ftdi chip to avrstudio. I see two competing app notes on the atmel site (avr230, avr231 [aes bootloader/des bootloader]), as well as a 3rd mentioned in the butterfly documentation (avr109 - self programming). Which one of these should I start with? Modifications I need to make from there - security is not of the highest concern, compatibility with avrstudio is. How have people implemented entering the bootloader? I suspect the best option is to send a "special" string over the uart, and upon recognition, jump into the bootloader - has anyone done that? If course, errors in application code could lock out reporgramming, so perhaps the bootloader waits one second for commands on every reset before entering the app code? Anyone 'been there' before?