i was also toying with the idea of splicing in some images of fish into the film and and make it a bit more psychadelic.
there was this footage of a fishtank

http://www.archive.org/details/My_Goldfish

http://www.archive.org/details/My_Goldfish_1

but i decided to keep it as footage of fireworks for my project.

using final cut pro, i used layered the footage of fireworks on top of each other, using cross fades to go between them, fading from cut up piece of footage to the other, i also used key frame effects to play one clip over the other with the black of the night set as transparent.
i tried to line up some of the explosions to go off at different points along the timeline to meet up with beats of the soundtrack.