A very short and not very comprehensive list of of fan produced Star Trek-based shows, and the occasional original series production.
Star Trek Farragut
US based production, also does an animated series.
Star Trek: Hidden Frontiers (HF Productions)
Also home to ST Odyssey, Helena, Henglaar, and original product Frontier Guard, https://www.youtube.com/user/FrontierGuard
Seven seasons of STHF, two seasons of STO and STH, Audio only Henglaar, MD (he's a Tellerite).
Star Trek: Intrepid
UK based crew.
Star Trek New Voyages / Phase II
Fourth and Fifth seasons of Star Trek.
Star Trek Unity
Aging ship, oddball crew, vodka on the desk in the ready room.
Short (under 10-15 minute) episodes, with occasional full length episodes.
Star Trek Phoenix
Very nice production values, one episode.
Star Trek Dark Armada
An interesting take on Star Trek from Europe.
Not just Star Trek. Doctor Who, Orginal sci-fi and horror. Audio only, downloadable MP3 files.
Very good and strongly recommended.