I have been looking through all my blog entries while categorizing them, and realized there is not one entry about a major hobby of mine for the past (at least) year, my carputer!
My first foray in to the carputer world was actually back in 2002, freshman year of college. I bought a Pentium 90 off one of my suitemates, a new motherboard (which I bought at a computer swap meet at the Scottish Rite Center), and built a custom wooden case and built a 5+12v power supply to work in a car. The carputer didn't have a hard drive, it booted off bootable cd-r's with dos and a simple mp3 player, and stuffed with mp3's. The control was by a numeric touchpad. It didn't work very well, and I think the problem was that the cd-rom drive sucked too much power and my tiny power supply couldn't handle it.
For my 25th birthday last year, my wife got me a newer Mini-ITX motherboard, case, and 7" touchscreen. This computer works much better, and I have been using it successfully as a media library for the past few months. There was a lot of new hardware built specifically for automotive computers in the 3 year gap, and this time I didn't have to build a power supply. The power supply I have is made to switch the computer on and off when I turn the key in the ignition. I haven't found a good enough (and still free) mobile navigator yet, but I'm working on it. I have a more detailed write-up on my site, hackmyride.com.