Amusing post on slashdot where guy with somewhat similar question was
by the community ..... but then maybe his business is spammy, and he is certainly foolish to want to be paged on a hike, and he should have other folks backing him up, etc. etc.
those details aside, as hard as it may seem to believe, there are still large areas of the united states still with extremely weak-to-zero cell coverage. not large population areas of course, but large pieces of countryside. (nice places to live and work, btw, because of the lack of population, imho!)
so while email->text->cell is a nice option, it doesn't work for me, at least for now, due to ruralness....