I began making USB desktop extension devices in early 2004.  My first design was a n LCD text display.  My second design was a USB RGB lamp.  This first proto uses the USB high power mode and a high-brightness RGB module by Lamina.  I designed the PCB as a retrofit to a cheap Ikea lamp.  I wrote a simple VB app to test basic functionality.  It works beautifully.

Check this out.  This is only vaguely related to ambient informatics, but it is inspiring for its out of the box thinking.
There are lots of great water ideas for ambient informatics: someone at Stanford made a fountain, the height of which was driven by the Dow.  Of course, they used bootloads of clunky and complex computing resources to make this happen.  With Atmosphericon you could create the most basic D-A pump driver mechanism, and a simple script on the PC side could drive it.

What about many pumps, or many valves, each tied to a different data source?  What about pulling the color aspect from the above idea, so that each data source was easily distinguishable?  This would be beautiful!  See the water music machines of Trimpin for more valve fun.  (can anyone find me a better link?).

What about weather?  A fountain might be a nice way to indicate weather predictions.  If, as you head out the door in the morning, your fountain is running strong and high, you had better take your umbrella!

I plan to make FireFox the interface engine, and web services vehicle, for Atmosphericon.  Why?  Because it is designed to be customizable and extensible.  Firefox is far more than a browser.  It is a platform-independent rapid programming platform.  Using it as my base, anyone can quickly script custom functionality for my devices.  Firefox is supported by a vast, creative and dedicated user community.  This community will, once I prove to them that my ideas are worthy, help me grow the Atmosphericon indea into a complex world of as-yet unimagined ambient informatics.

Here is an interesting quick take on the future direction of FF, which suggests that they do realize that extensibility is their strength and that they plan to capitalize further on this.  This is great news for Atmosphericon.

Freescale makes some tiny micros which might be useful for very small, inexpensive solutions; ambient sensors, remote devices, smart tags, assist devices.   Way less than fifty cents.  Not very powerful, but small (2×3DFN, six pins).  Limited debug, no ADC, memory paging, no interrupts?  May be wrong about that.

More expensive but much more powerful are the S08QG series, in 8DFN.  No paging needed.  More timers.  There is also a part family in between these, but it apparently is avail in SOIC only.

Here is a comparison guide.  I believe all use the single pin BDM.  Here is a sheet on the debug options for the three device types.  Here is a concise comparison card for the various small package offerings.  Here is a useful comparison between the high end and low end two, which also covers low cost demo boards.  Freescale offers online demo boards (Java driven simulators) and many online microcontroller training courses.