I often find myself wandering around in circle in Dalaran while just chatting on vent. The time could be spend fishing, mining, or doing anything else, but it's nice to just do nothing sometimes.
On a more in-depth note, if you haven't checked out Spore for some time-wasting, I suggest you do. The amount of customization in the game is unreal. I can spend hours just creating a space ship custom to my liking that I get to fly around with in space and explore thousands of star systems with!