Want some real home theater bragging rights? Instead of buying a projector capable of casting a 14-foot image at 1080p (progressive) resolution-the highest high-definition there is-build one yourself. After all, the front projector´s innards are simple: an LCD lit by a superbright lamp, and a few lenses to magnify and sharpen the image. Retail models start at around $800 and use proprietary $400 lamps that burn out every few years. But cheaper lamps work equally well, and none of the other parts are very expensive. Why not put one together yourself?