If you've got your own programmer, you can technically use the internal oscillator, disable RESET (which will be the last thing you ever do to configure the device with said programmer, but on the positive side it gets you an extra IO). Go completely insane, leave off the 0.1uF noise filter cap between Vcc and GND, and you can use the bare chip with only regulated power and ground.
Wait - use the low voltage part, and we can run directly of batteries, and skip the regulator, too!
Mount the chip dead-bug style and you don't even need a board.
Adafruit recently started shipping their "USB BoArudino", which is probably about as small as you can get with a DIP ATmega. If you really need a smaller physical size with USB, you're probably stuck doing your own board...
Thanks - the USB Boarduino is especially nice as the FTDI part is pre-soldered, and the other parts are supplied.
I was thinking of searching for a solution with a smaller pitch size of the I/O pins, or even looking for small footprint molex type connectors, but I think the DIP I/O pins would actually be really useful.
An ideal then would be a solution very much like the USB Boarduino, along with with a pre-soldered SMD Atmel chip (as used on the Arduino Mini), which would offer a smaller footprint.
Hmm, docs say 20MHz in one place, the picture and another place say 14.7456MHz. Doesn't leave me with a good feeling for the quality of the documentation. Create a new board type with Arduino 0011's capabilities and the clock speed should be OK, though.
It uses an SiLabs USB/232 chip - bummer. Their driver caused a kernel dump on my Mac OS X machine (the only software to ever cause the kernel to dump). I have used a number of different USB/232 chips, and the FTDI is far superior to all of them (especially if you use more than one device at a time, or if you need cross platform support).
Pass - I'll stick with one of the FTDI-equiped Arduino or Arduino clone boards. There are plenty to choose from.
As I mention there I would like to make an even simpler lower part count version too mainly for those times when you have a processing app that needs to read sensor values or something from just 1 or 2 things. The 168 seems like a waste though so maybe it would be possible to get the bootloader on a smaller AVR....?
edit: w00t - 51st post and no longer a newbie. Only took 2 years!