also check out
mini-itx.com
I've posted several times about mini's...I have one and I'm typing on it now!
no games, no UD, no high-cpu stuff, but I do use it for mp3's, the S-video comes in handy for on-the-road usage...and I love its tiny size! my whole puter can fit in a napsack!
it's really quiet too.
I have the C3 800mhz Epia-V, which I paid $89 for, on eBay.
it uses sd-ram, up to 1gb...I have 512mb
it has tv-out, rca-out, onboard LAN, 2x usb, vga, printer, parallel, and the rca-out can be configured as well. three audio jacks- line in, line out, mic.
I have a 150w psu, and a disk burner. three 40mm "case" fans. it's quiet as h3ll!
mini-itx is good to experiment with...also powerful with linux!
~Branson

above all, just have fun with it!