I ran up to Barr Camp a few weeks ago, I was able to text with my wife in Manitou from there and from the W's. Verizon is my provider, your results may differ.
In response to:
I am doing the marathon on Sunday and my wife and son are probably going to only see me at the start and finish. My plan was to bring my I-phone with me and at maybe two point during the ascent to text her that everything was ok and maybe once on the decent. I will move off the course when I do this and I will not block people behind me. My question is is there even cell reception on the mountain?