hehe, Thanks :)
Just nice to help! :D

I've created this animation Click here (http://www.elqx.com/studios/site/xite/movies/lightsabre.wmv)

And yes, you can use a cylinder too.

I did some tests and to get that effect you need to use a
Jiggle Deformer insted of motionBlur.

Create a cube a make it the same way as the pic.
Then select the points selected on the pic and...

Is this what you want? (see attachment)

If so, It's just a normal Lambert with a Green Color.
And both the Ambient and Incandescence up to full.
Plus the Glow Intensity to 0.200.

Hope this...