It's always baffled me why super bright white LEDs aren't used in any DIY projectors I've seen online as a relatively small array of them is capable of some very impressive light output at a fraction of the running costs or temperature produced by filament bulbs. They're not even that expensive anymore (certainly when compared to commercial projector bulbs) and could provide a much longer lifespan than filament bulbs.
Sure, they may not be the 'perfect white' required by expensive commercial projectors but has anyone tried to use them in a DIY LCD projector.
Also, what about those flourescent 'low energy bulbs' that claim to offer the equivelant light of a 100W tungsten bulb whilst drawing only 25W of light? Wouldn't using a grid of them behind the LCD screen with a small reflector behind the lamps provide enough light?