On less than 10K runs I only carry id (Road ID on my wrist) and my house key (in the mini-pocket of my shorts).

Over 10K I am likely to have a fuel belt (which has a little pocket) or a hand-held water bottle (also with a pocket). I will then carry a bus ticket and/or my credit card, and a gel or two depending on the distance. I also have a skin-tight Sugoi top that has a small pocket at the back.

For me a cell phone is totally overkill because I run within a city or urban trails only. The weight of it would be unpleasant, bouncing around.