Since your flight does not leave unitil evening how about seeing a baseball day game or visit a great pub/restuarant in Tempe. If you choose Tempe I suggest going to Casey Moore's Oyster House which is a pub like house built in 1910 and sits in a residential neighborhood that has character. Something different in town filled with shoping centers and trac homes. Eithere choice the time is minutes and you can travel for less than $10 via cab or take the light rail.