/#\ Available for the retail market, at the moment, in sizes suitable for domestic lighting. And even then, it's really just painfully expensive, not impossibly expensive. Electro-luminescent panels are on the market with output efficiencies up in the 90s of %, and extremely low heat output per unit of light. Heat outputs low enough that you can't notice them. But their sizes are limited to hand-held computers, and limited colour availability ("white" isn't particularly white). Cold-cathode lamps have been used in LED screens for a good few years now, and also produce negligible heat at significantly larger sizes than ELs are available for. Still not big enough to be usable for room lighting, but it's getting within reach. Look at the number of 15" and 17" flat panel computer monitors and TVs being made, and think of the volumes of lamp production that implies - putting a flat rectangle of cold light on the wall is already an expensive, but credible, way of providing in-fill or mood lighting. Oh shit, I'd better not let the wife see that.