I just noticed that the transporter has a number of implications that the various series don't focus on even though it seems they would be rather conspicuous in their effects on Federation culture.
First, even given a presumably limited range, the transporter implies that instant teleportation--which I dimly recall being at the top of GURPS Ultra-Tech tech levels--is already present in the Kirk era, but apparently no one has noticed. What I mean is, with a network of transporter relays, ships are probably unnecessary for travel between settled locations of Federation space. So, that's the first seed of my new campaign setting: A team of transporter relay installers, out of the frontier. They would need a ship, but probably not a fancy one. Tradesmen in space!
Second, I don't have episode citations, but there's one in The Original Series in which a person's transporter-code self is stored in a belt for later retrieval, and one early in The Next Generation in which Picard is restored from an archive copy of his transporter-code self. This means both that immortality has been achieved and personal identity, at least in terms of being a single enitity, is now outmoded. That is, there doesn't seem to be any obstacle to making infinite copies of yourself forever. So, Starfleet officers should probably be issued Immortality Belts with the ability to 'beam out' copies of themselves in the event of death--and away teams should probably just be made of copies (avatars, even) of the ablest bodies for the mission at hand.
Third, this is not related to transporters, but the Doctor of Voyager and his emitter raise the possibility of rouge holograms, so: Haunted Hulks. I'm sure the galaxy is just filled to the gills with space stations overrun with horrid fan-fictiony holograms endlessly murdering teeming copies of Wesley Crusher's loin-clout-clad barbarian-self as he tries to rescue a gender-swapped Picard-in-distress from the Traveler-beast.
So, what do all of you know about these ideas appearing in the various series--and novels, comics, etc.?