A big heap of new guidelines were just published for Star Trek fan films to avoid lawsuits. They pretty much suck.
The first one limits your film to either a single 15 minute episode, or two with a limit of 30 minutes total.
Considering I've toyed with the idea of making a fanfic audio drama podcast set on a Starfleet ship, this isn't great news for me. Not a film, sure, but I imagine they would apply the same rules, which would kill the plans I had for a couple very long story arcs. I was nowhere near ready to make it, but it was a fun project to play with. Might still try it if I can bring myself to pry all the trademarks off it.