I like my iPhone 4 and don't feel a need to upgrade for the foreseeable future.
Being 50 now, I can clearly remember life without cellphones. I'm happy having one, as it's come in quite handy at times I would otherwise worry. In fact, recently when driving to LA, I called 911 (yes, while driving) and reported, in a highly emotional voice, witnessing a car assuredly having gone through a guardrail on the freeway--because I heard a "BOOM!" and saw a car flying through the air, off the freeway where there was nothing under him as he epbegan falling the 20 or so feet to the ground. No, I didn't stop, because I saw a big rig and a couple of cars stopping. Since I witnessed it (enough), they decided the call and said they'd send people immediately.
And I'm sticking with AT&T, despite not always being thrilled with them, because I got "unlimited data" grandfathered in, though I seriously don't use it all that much.