[AtlUmpSteve]

Personally, I do not tell coaches that they cannot have cell phones on the field. What I tell them is if they answer it, or look at it on the field, I cannot and will not guess what they are or are not doing, and would have to disqualify them from coaching for the rest of the game.

Generally, they either remove it, don't answer it when it rings, or tell me a story that I can live with. These instances include I am on-call at work, and it is a remote possibility that I would be called, but I will accept the penalty if it happens rather than lose my job, or (heard this several times) my wife is expecting any moment, and I have to know if she goes into labor, or something similarly valid.

Just how I, personally, handle cellphones, PDA's, pagers, etc. I did once have a coach get an urgent text message, which he immediately showed me, rather than risk me thinking he was cheating.