I got an iPhone, and it's now my indispensible portable device. I use it constantly. I can't wait until the 3G ships, so I can throw away my still-perfectly-usable $500 phone to buy a whole new $500 phone that does the Intertube faster. But here's the interesting thing: it's become indispensible in ways that I didn't expect it to before I got it.
Way back in the day, I used to compile all my sources with scripts. That lasted until I started doing Unix development, when I was introduced to "make". My first reaction was "why do I need that? I can write scripts to compile stuff." I was, of course, completely wrong. Completely, amazingly, agonizingly wrong. "make" was a whole different way of dealing with that particular underlying problem, and having once found "make", there was no way in hell I was going back to a non-"make"-having environment.
Same thing when we got always-on broadband connectivity (back in like '98 or '99). Up until then, we would occasionally go and dial-in to check email, but it was always a specific "go and check email" task. Once the broadband connection showed up, though, our network usage went way up. Not because we checked email all that much more often, but now the WWW was no longer unreasonable. And once again, having once found always-on connectivity, there was no way in hell we were ever going back to occasional dial-up access.
This pattern has repeated itself several times in just my personal experience: a technology comes along that beforehand I couldn't imagine why I'd want it, but afterwards became something that I couldn't imagine doing without it. "make", broadband, TiVo, and now an iPhone.
Kathy got the first iPhone in our house because she said I could take the birthday money she'd already gotten and just add the difference to get her one for her birthday. I did, because she deserves cool things in general, and whatever she wants I like to get her. I got one because I too deserve cool things, and she kept taunting me with "my phone's better than your phone."
Now that I have it, I find I use it constantly. Not for making phone calls, mind you. I probably don't use its "phoneness" more than I did my previous handsets. I use it all the freaking time as a portable Internet device. At this point I'm really glad that Steve and the Death Star made me get an unlimited data plan because I am sucking the bits out of the aether all the livelong day.
I can't even watch television anymore without my iPhone in hand (well, I'm watching TiVo, but you know what I mean). Previously I was unlikely to pause the show and wander off to the other room to look actors up on IMDB (one of the most common things we say while watching teevee is "I know that guy/girl/child from somewhere!"). Now that I have an iPhone in-hand, I do just that. All the time. I read my RSS feeds at the gym. I twitter. I facebook. I hardly even notice standing in line for random crap any more because I always have something to do while waiting to check out at the grocery store or whatever.
And I do all these things because they are now significantly more convenient for me to integrate them into the non-digital portion of my life. It isn't that they weren't there before, but they were previously walled off into their own domain. Now that they're everywhere that I am, I can use them to keep informed, to talk more loudly via twitter and blog, to research more deeply, to remember more broadly, and to listen more carefully.
I can't wait until The Steve invents an implantable iBrainPal so I can quit typing with my thumbs.