Have you ever heard of "spinning steel wool?" If not, it is a lot of fun and a very photogenic activity. Basically you light steel wool on fire and photograph the sparks. You can see examples in my night image gallery.
I have 2 complete setups, basically a metal cooking whisk with a cable attached to the handle, and I think this would be a lot of fun for the group. This is long exposure photography so a tripod, or some other way to stabilize your camera, is required.
We have a date and I am scouting a location or two and will update that as soon as I can.
I am open to locations, but I think that the fountain in downtown would be pretty awesome, I wonder if the city would have a problem with that? Obviously the other requirement is that it will need to be night/dark. :-)