My idea is to build a homemade projector, either inside a scratch case or inside a microatx case, with the mini itx powering it. The case would house a mobo, terabyte hdd, bluray drive, and a psu. The projector itself is simply a 6/7/8 inch lcd stripped to the bare display panel. A light source shines thru the panel reflects off a cooled mirror, through a focusing lens and onto your wall. The light source is often the expensive part of a home projector, so to hit the budget the light will instead be an array of ultrabright leds. This will also lower the internal temperature of the projector. The lcd panel also needs adequate cooling to prevent burning, hence the fan mounted near the panel. This idea is great for a lan, backyard party, or simply a htpc setup. Who doesn't want a pc powered 20' display!
ultrabright low angle leds
(ps go boddaker!)