I read one scifi novel where the teleportation was almost instant across the galaxy, the caveat was that it duplicated you, so the original walked out of the booth, while the copy was the one who actually went somewhere. Aside from the issues of having several of you around if you went back to the destination, not every teleport was great for the original either. One instance where they were trying to escape some creature planetside, and as they ran into the booth the main wondered if they'd be the one who made it to safety, or not. Of course next chapter picks up with the safe one's pov....