You can achieve this kind of specular bloom in your renders by using the Blur Rendering Effect.

First, add Blur to your scene (Rendering ... > Effects ... > Blur) and select the Pixel Selections tab underneath. Instead of Whole Image, select "Luminance" so that you are only affecting the brightest pixels in your render. Bump up the Brighten(%) value to whatever is applicable to your liking, and then increase the Feather Radius to the amount of blur to add to the glowing halo effect. Start low with the radius (i.e. 5%) and high with the Luminance (100%) and then adjust as you see fit.

Give that a try and let us see your results!

That's a cool tutorial,  but I think that it's more of a reflective glow than the result of an emissive glow (like a neon light). 

Dunno, maybe it works out the same... just seems to me the mechanics are different. =)

"Glow" is seems to be a misnomer for this effect anyway.  I think Elyptic named it well with "bloom" (photographic term?) that suits it well.

Very nice technique, elyptic!  Thanks for sharing.

As an alternative, there's also the Diffuse Glow filter in Photoshop.

(@elyptic: I used your pic without asking. If you think it's bad, I can remove it...)

Thanks Elyptic, that's kind of you.

Sure Photoshop is is not going to help learning Max/Mental Ray. And it's definitely no good for an animation. I thought of it as an alternative for a still when your in a hurry.
My excuse? (lol) I'm deep in Photoshop help files and tutorials these days. A bit over enthusiastic perhaps...  8 )