Not sure if this is the answer you are looking for, but have you tried LuxRenders Bloom effect (in the Lens Effects Panel). I found that works quite well with lasers. To test it just create a long thin cylinder, rename it to RealityLight (you have to add another object to the scene but it does not need to be in view) and call Reality. You can choose a preset or go straight to LuxRender.

In the Lens effects-Bloom, just press Compute layer, wait for it to calulate things and tweak the settings, it will automatically adjust the effect as you move the sliders so just have a play and see what happens.

Not sure about making a screen glow, but I will have a try. I think Doc has managed it though.