Yup, that's how I ended up with an iPhone. I bought an iPod Touch when I was traveling a lot, and wanted to be able to watch movies on the plane.
But, since it has all the software of the iPhone (except the stuff specific to the phone), I was able to see how well the email client (IMAP, Exchange integration) and web browser worked, I decided to upgrade to the iPhone.
I waited until the 3G came out. Then, I sold my iTouch. The iPhone is by no means perfect, but it's better integrated and more functional than any smart-phone I've had.
The iPhone is by no means perfect, but it's better integrated and more functional than any smart-phone I've had.
AND..., the really nice thing about both the iPod Touch and the iPhone is that any improvements and upgrades to the device (either one) is a simple "software upgrade". With that, they give you new functionality that you didn't have before and new features that weren't there.
All the other phones that I've had were "locked into a feature set" that came with it when I bought it and nothing past that, no matter how long I had it.
But, with the iPhone (which is what I have) and the iPod Touch, I've seen upgrade after upgrade and added functionality and more, ever single time there was an upgrade. And it was simple, just clicking the software download -- and you got a "new phone" (or a new iPod Touch... :-) ...).