Here's the Ardweeny from Solarbotics. It's an Arduino system based on Kimio Kosaka's One Chip Arduino. I got it partly to have a small, cheap Arduino for breadboarding, and partly to practice soldering on a real project. I'm going to use it to write some code to understand the AT interrupt driven timer. It will conveniently hang off my laptop nicely without the size and weight of the Uno board, and provide a second processor type to force dealing with the hardware differences.
Here you can see that it's soldered to the top of the ATmega328P. You can see one pin with much less solder than the others, but it's firmly connected to the chip. I'm not sure which is better. If you have an opinion let me know in the comments.
To program, you need an FTDI adapter. Note that there's a tiny "-" on the board that lines up with the BLK connector. The Ardweeny can be powered from the FTDI adapter. It has a reset button and an LED on pin 13, so you can run a standalone blink program!
Here's a shot showing all seven (!!!) components and the pin names. To program, choose Duemilanove/328 in the Arduino environment. I'm really impressed with the parsimony of the design. I think on a future page I'm going to go through each of the seven components as a learning exercise and document what each one does.