I have several clips I rendered of a battle between human and alien space fleets. I think I can offer some advice if you want. Unfortunately, I don't have a website currently, but if I compress a file with Divx or somesuch I could email, or FTP you an example. The ships were built in Wings, but the beam FX were done by animating Bryce cylinder primitives(parented to each ship) and adjusting their material ambience,transparency and position/length. It really can be done quite effectively. When I render an animation I usually save it as a .bmp sequence. Here's a frame as an example.