Line models possible?

I'm not a moddeler/animator so I figured the best place to ask would be around here...

Is it possible to make a straight line that connects two units? Like healing wave, chain lightning, life drain, etc. do. But rather than anything fancy, just a straight line. Furthermore, would it be possible to make the effect last forever, even as units move around and stuff? You could use this to create effects like FPS style grappling hooks or trip wires or lasers of various kinds. I figure this would take some spell editing as well as model editing. Ari said a ribbon emmitter might do it.

Is it possible?

*bump*