Big TVs are getting cheaper all the time, but 100 inches still costs a bundle unless you want to muck around with a projector, a screen and a dark room.
Sony has a couple of solutions for rich buyers who want a TV that big. One is the XBR-100Z9D, a 100-inch LCD TV that costs a cool $60,000 if you can find one. Another is the VPL-VZ1000ES, a relative bargain at $25,000. It's available for preorder now and ships in April.
It's not exactly a TV, but it comes close enough. It's a short-throw projector, meaning it can sit within inches of the wall and still project a huge image (you could get up to 120 inches or more if you wanted). It can blend seamlessly into a cabinet and the whole system can disappear entirely if you spring for a motorized screen. Of course the price is well beyond most people's budgets, but it still represents a cool concept and a different take on traditional TVs and projectors.
One downside with projectors is that the image washes out in bright light, but the VZ1000ES has a couple of fixes for that. One is sheer light output: its laser light engine puts out 2500 lumens, very respectable for any projector. Combined with a specialized screen designed to only accept light coming from below, as demonstrated in Sony's booth at the Consumer Electronics Show, you get a massive picture that's bright enough for most rooms.