Note that even lists can be tricky. This is because if you are Horde faction, you wouldn't want to consider entering Ironforge or Theramore or Loch Modan as counting as "entering town" because its owned by the opposite faction.
In this case, you may want 3 lists of towns: A horde one, an alliance one, and a neutral one.
I understand your concern, Tekkub. The reason is because I am casting a spell that doesn't need to be cast in town. Besides, Blizzard hasn't implemented player housing yet, so there is no place to crap. And sometimes when I crap, I'm not resting... ;D