Attached Link: http://www.renderosity.com/gallery.ez?ByArtist=Yes&Artist=erka

Nick, take a look at the image "Bridge/3(Urbania)" in my gallery. This is what i did to get the neon signs effect: Use a luminous material for the neon itself, with a bit of glow added. Position a few omni lights with the same color as the neon material in front of the sign. Adjust their power so that they light the background wall, giving the impression that the light actualy comes from the neon itself. It's important to use more than one light in order to get an "area light" effect.