I have a slightly different perspective -- I've had a cell phone since Voicestream was a carrier in the US (late '90s?). And, get this, I still have the same phone. Funnily enough, it makes and takes phone calls just fine.
I've thought about upgrading to a camera phone, or something I can SMS with (I can receive 'em but sending I've never figured out). Except a) I don't like being tied to a contract (although I could get around that with an ebay buy), and b) I don't want a monthly bill. I went pre-paid a couple of years back. I just don't talk that much to warrant the monthly fee, and I emphatically do not relish the idea of an expensive monthly dataplan fee. (Anything over $20 a month I'm going to consider expensive.) On the other hand, a one-time purchase of a useful IT is reasonable. If it were married with a phone, though, I'd much more hesitant about purchasing, for fears of functionality being impeded if I didn't also spring for a monthly phone and/or data plan.