Dick Lynch, Verizon's chief technology officer, was one of the first to try to say that cell phone customers should be billed according to usage, "just like water and power companies." AT&T quickly took up the message and ran with it, and now currently charges for data "like water." Meanwhile, Verizon sits on the sidelines letting AT&T try this new experiment in pissing customers off. As I've said before, data is not like water, and it's stupid and misleading to try to charge for it in that way. Which is why no other major companies have followed AT&T off this cliff so far. (They're offering a low budget tier, but so far none are charging like AT&T per gigabyte.)
But here's an interesting article that talks about cell phone uses, and how big companies can rip people off by supposedly "providing water" service: