In SF (as in life), there is always a problem with interstellar travel: Those damn stars are really far apart. Now consider physics: There's not much room to hope that we'll ever travel faster than the speed of light. If a science fiction author wants to send characters from one star to another and have them arrive before dying of old age, something's got to give. There are several standard solutions to the problem:

I hope I didn't miss any.

1 Thanks to Demeter and Gorgonzola for reminding me about Ender's Game et seq.

2 Thanks to Gorgonzola for calling me back to the ochre vegetation etc. Gorgonzola prefers to refer to John Carter's trick as "astral projection" rather than teleportation. He concedes that the distinction is a subtle one.