Hats off to you Mbai2,
I didn't know there were any fellow hardware hackers on this forum! Here's a site to some guys who've been doing this for a few years now, using Linux. They have all of the software downloadable.
http://www.dashpc.com/
I haven't read the original thread to see what hardware you used, but VIA makes the mini-IPX motherboards for this purpose. All-in-one gigahertz Pentium class motherboards that draw about 15 watts, in a 6.7"x6.7" package. A 600 MHz unit is fanless and strictly heat sink cooled.
Go to
www.mini-itx.com for details on what others use this mobo for. And to
http://www.mini-box.com/site/index.html for cool accessories (fanless power supplies, car sequencers, compact flash adapters, etc).
If you have heat problems with a 3.5" hard drive, go get a 2.5" laptop hard-drive. It's about 1/5 the power, and you can get an 80 GB Samsung unit that spins at 5400 RPM for around $110. They're also much more tolerant to vibration and shock.
Edit: I just read the previous thread and I see you used some of these sites, and the Mini-ITX board. Very cool. With a big enough, low power hard drive, and a USB port, who needs a CD player? Rip all your CD's to MP3s!
BTW - what's the boot time on it?