FlyingUnderTheRadar

Having recently had this conversation, one first must ask is it Travelling - but who with? or Travelling - but with whom?

Grammar would dictate that who is used as a subject whereas whom is used as the object of a verb or preposition. So the latter. But I digress.

I have done all on your list including "other" if you count my dog. It all depends on the trip and its purpose. It also depends on what you mean by traveling. That could be a day trip or multiple days.

The founder of Lone Planet, Tony Wheeler said something to the affect of, do not worry about what or with whom to do when you get there, just get there. I think that applies.