Well, this requires a bit of setup and isn't perfect but seems to get the job done. Usefulness will depend on what you're wanting it for I guess.

For each toon:
  1. Assuming you don't want to use your mouse for this, bind a key to "Move and Steer", let's say 'X'.
  2. Use your mouse to position the camera so that it is facing the toon, and /run SaveView(2)
  3. Make a macro that does /run SetView(2);SetView(2)
Then, to do a 180 turn, hit the macro, and tap X.

[s]Note that when calling SetView() the game will try to make a fluid transition from whereever your camera is placed to the saved position, so this isn't really instant.[/s] Thanks to Slivermaster for solving this: calling SetView() twice in a row causes the camera to snap into position.

The 2 there can be any number from 2-5, (1 is reserved for 1st person view, you can't change it).

You can /run ResetView(#) to restore the default camera position for an index if you ever want to.