I am currently in a job where I am a triple threat..
Executive Assistant/ Office Manager/Personal Assistant.

I can tell you that the Personal Assistant activities are the WORST!

I wanted to get away from it but the non running around items like the shopping, and appointment setting is a good idea to incorporate.
With gas prices there is NO way I would do it. But then again, I work with an out of control, ego driven, young professional. So my life pretty much sucks when I have anything personal to do for my manager.