The holy Grail of toys has to be the 'real' light sabre.
How could such a thing be made?
Lasers are no good because they don't just come to a halt after a few feet, and they are difficult to see unless you have a smoke machine.
Some kind of jet of hot gas or plasma might work, but may be a bit too realistic and incendiary.
Something that would give the turning on effect of appearing from the handle would be great!
Any ideas! There must be some pre-cgi special effect way of doing it.
I think Lucas arts used film composting 
I dunno maybe if you took a laser beam and had a complicated mirror setup so they would intersect ... kinda like multiplexing a led matrix? (then you would still have a zillion laser dots on the wall and shoot someones eye out)
A thin lightweight semi-transparent fabric in the handle, along with a small fan and some LEDSs, just make the fabric into the correct sabre shape 
I think Lucas arts used film composting
Next from Lucasfilms, digital film mulching. ;D
I like the fan and cloth idea. The fan could reverse to suck it back in ! Schwuuup.
Next from Lucasfilms, digital film mulching.
yea OK I had just woke up (by my mutant kitten biting the fire out of my toe) and firefox did its little red line thing
BUT! lets be real here the prequels were compost (wah NOOOOOOOO! haha)
I like the fan idea but its going to be difficult to keep that rigid while boffering, unless you use a strong fan, but then I dont know if whir = wosh / vomp in the sound department
Maybe an electric car antenna, with a disk on the end with a circle of narrow angle LEDs (or laser modules) facing back towards the handle.
You'd still need a a smoke machine to see it though. But that would allow for 'boffering'
well maybe you could do the sock with the antenna in the middle, I know motorized antenna's are pretty reasonable in price
A bit fragile for a lightsaber maybe... Also rather slow.
Sock and antenna is good, because the sock could be blown out quickly, while a short delay for posing would allow the antenna to catch up and provide rigidity.
Or,
How about this - instead of a cloth 'sock' how about one made of thin polythene, blown out under pressure.
However, the slightest puncture could lead to a certain lack of rigidity, and the last thing any Jedi wants is a limp light sabre.
I may have gone too far here..
Dark Helmet: You have the ring, and I see your Schwartz is as big as mine. Let's see how well you handle it.
You mean like this Class 4 Laser?
Warning: Might cause Super Cancer on skin and reflection of the beam on un-protected material will surely: Burn, blind, kill and potentionally cut you into pieces.
(for those who noticed it: I consider that you can be cut into pieces before dying. That is why I separated the two options)
A tube of plasma would be pretty realistic.
What you really need is the plasma contained by some kind of field, most likely magnetic.
I'm not altogether sure where you'd get and maintain plasma from, but nuclear fusion is probably your best bet.
Just use the force and you should be golden 
One way to do it is with a long tube of clear acrylic attached to the light sabre handle, inside the handle is a resevoir of water and a high mcd led or laser, holding the sabre down and releasing a valve on the handle lets the acrylic tube fill with water and looks like the sabre is extending, closing the valve holds the water in the tube, holding the sabre upright and opening the valve lets the water back into the handle so the sabre retracts, to make it more visable very fine glitter powder is added to the water.
Thats how i would anyway