I give people the number of a phone that I carry on forum rides but it is the only time I'll answer it! If anybody wants to contact me any other time they can email me or PM me here and I'll reply at my leisure!
I very rarely carry a phone when riding solo. If something bad happens, I'll cope with it, or not, just like people always did before mobile phones came along.
It pees me off when people start taking lengthy calls during rides. One mate got 3 or 4 calls during the 5.5 mile Cragg Vale climb with me. His girlfriend was in a supermarket and was asking him if he fancied mackerel? 5 minutes later - special offer on red wine. Ooh, must make another call - what do you fancy for tomorrow night ...? I told him to tell her that he was busy and get on with the ride or I'd leave him and go on alone - flipping heck!