Hacking Your Car: Install Windows on a CompactFlash Card looks pretty interesting.
Take something like a surplus fanless x86-based Thin Client, pull out the flash module and replace the software on it, and drop in your Hacked Windows XP... and you're on your way.
A lot of those units use a small card with flash memory that plugs into a laptop (44 pin) IDE socket on the board. If you can't figure out how to reflash that (or it's too small) you might drop in a fast CF-card and CF-to-IDE44 adapter.
And no more Linux grief! You can write your own code to run on the thing without resorting to caveman level coding in C or Java using tools predating the Harvard Mark I.
The basic idea described there is to start with a few bits from the XPe Trial package (which will expire on you, so no go) plus a retail full XP license and build a full XP safe to run from flash. You take a fresh XP install, turn off paging and indexing, etc., strip out stuff you don't need using a 3rd party tool if necessary, and then graft on a few system files from the XPe package.
I especially like the Hibernate Once, Resume Many option to make rebooting even faster.
This might be useful for lots of things. Webcam servers, robots, NAS, whatever.
Has anyone tried anything like this?