Wow, I didnt expect such enthusiasm, thanks everyone!
Hi Daniel, sure thing, I'll do my best to keep you in the frame.
I surrender Gizmo

Heres the LCD screen I will be butchering (attached).
RussianMissile1, thanks for the diagram. I reckon I'm going for air, using 10 Tornadoes at .001V

Just kidding, but I'd better draw a diagram of what I'm thinking..... (attached)
If you have more ideas throw em in.
Damn thats rough, it gets the idea across I hope..
Nothing is to scale btw.
The fan is intended to be silent. I want to have 2 fans, 1 each side of the LCD/OHP. One will suck, the other will blow. If one fan fails, the cooling should be nearly as effective.
Object(s) in the air tube will make the air a little turbulent before it reaches the LCD. This should help keep air moving at the edges rather than taking the easiest path across the centre of the LCD. Lots of trial and error to go on this.
I bought some ladies tights today

I'm using them as air filters (honest!)
The whole dual fan assembly could be dropped onto the projector as one unit, providing the mounts for the LCD also
I'm hoping to make this from thin plastic sheet (another thing to find) and a glue gun.
A fan blowing down on the top of the LCD would be beneficial. This would provide good cooling over the back LCD surface and give a little peace of mind. As I will have a hood over the whole projector, this fan can be used to draw colder air into the cavity rather than circulating. (a diagram moment?).
Throughout the project I'll measure the temperatures across the LCD surface. I'm stuffed at the moment though cos I cant find my spare sensors. May have to steal the one from my
CPU!
There needs to be either a fan failed warning or a high temperature warning. As this Projector will be silent (I can hope), so chances are I wont spot a failed fan.
Using this 3 fans method, it should have a pretty cool life
Gizmo, I was going to write about the same thing regarding oil cooled lights. It would be nice to get a cooled light in there as a real simple solution, I need to get some to see how they can be integrated, I've no idea of the cost yet. The projectors are setup to give a nice even spread of light, This may be hard to achieve with a different bulb/shape/size.
An oil filled cooling surface would be excellent. Do you know of any clear oils that catch radiated heat too?