how do I create a Ghostbusters beam

I think this would be possible with a procedural mesh, 1 drawcall but maybe a little expensive to calculate/render. Imagine a straight line between the player and the target, then divide that line into lots of connecting lines, imagine where each cut in the line is a node :

  |----|----|----|----|----|----|----|----| <- nodes

Find how long the beam is, calculate where you want 'nodes' and how many for the lightening to change direction (zigzag). Generate a mesh with 3 quads between each node, and update their verts to an offset with perlin noise, eg the first node goes up a bit, the second node goes right a bit, the third node goes forward a bit , etc etc =]

Something that works very similar to what I am describing can be seen in this free unity package, Procedural Examples : http://u3d.as/content/unity-technologies/procedural-examples/3zu

Thank you alucardj - this was very helpful - just the the example I was looking for!