Homebuilt or store bought?

So i've had an idea for a low cost laptop with a long battery life.

there's that "new" UMPC classification, but the models out now aren't mobile, unless you are only looking at weight.

imo, a true portable should be able to be completely untethered for no less than 8 hours, 12 would be better.

the issue is three fold as i see it. first, we have the processor. the x86 was never designed for portable use. there's some offshoots, pentium m, AMD geode, transmeta, but those just hide the problems. while the compatibility of the geode attracts me, and i dislike intel, i think arm is the answer. Mips looks good also, but arm already has a strong following, so most of the software is already written. even windows variants if one wishes to in that way.

the second issue is accessories. a true UMPC should not have any extras. i'd include one (1) each: type II pcmcia slot, flush SD reader, usb 2.0, internal compact flash, bluetooth and wireless. also mic in and stereo out. No speakers. if one wants to listen to music, plug in external speakers.

a true UMPC should have no moving parts. even the keyboard should be solid state. one idea is to use a touch screen as the keyboard area. the image could be shown, and respond to finger touch. custom layouts would become a software issue. you could even have per program layouts.

but why use a physical part? why not use a laser to project the image onto a surface? an interagal stand and transmitter(s) wouldn't take up much weight nor power. but why a stand? i'm not saying that we must get rid of it, but most people visualize a computer as a keyboard in front of a monitor. why? imagine instead a split layout with a monitor in the middle. i belive the pepper pad has this layout. but instead what if when you wanted to use a keyboard, you placed the tablet on a flat surface, perhaps a lap stand, and activated the lasers. you could type what you needed, press a button, and no more keyboard. Nothing to tote around.

Another thing is the monitor. i watched <a href=http://www.imdb.com/title/tt0280674/>The first $20 million</a>. while their holographic display is cool, it's still too far out to see them irl.

however it got me thinking about alternatives to conventional monitors, and a search found <a href=http://www.engadget.com/2005/04/06/scalar-corp-intros-7-gram-lcd-glasses/>these</a>. i'd like to see the price closer to $100, and a screen a bit bigger not to mention wireless or bluetooth, but it looks promising.