I suspect that many of you have developed small items to help repeated developments using Atmel chips (and others). If they have been useful to you, maybe they could be useful to others also.
I am willing to kick the list off with one of mine.
I have done several designs using the V-USB minimal interface ( http://www.obdev.at/products/vus... ) using software and a small number of external components. These have been done on the Mega8, Tiny2313, Tiny85 and Mega88 chips. To avoid the repeated exercise of doing a prototype for each processor I made a single pcb assembly that includes the USB connector for testing after code downloading, optional diode droppers from 5 volts to 3.3 volts, optional 3V6 zener diodes on the D+ & D- lines, a reset button, ISP interface to my dragon (or STK500) whose pins are then available for patching to the specific development chip, and a couple of crystals (12MHz and 16 MHz) with their load capacitors. This little board plugs into a breadboard and provides the ground and power rails while also providing the mechanical support for the pcb.
Any other contributions?