I find the iPhone's UI snappy and responsive. Tethering in Canada is not an option because it's still ridiculously expensive; even if you buy 6GB of data, they insist it's on device only.

The camera is pretty decent albeit doesn't have a flash. Many of the free apps are quite useful. Web browsing isn't bad at all, you can have multiple browsers open. No flash yet but there is a youtube app that comes with the phone that works quite well. Obviously the music playing functionality is just as good as the iPods...

Overall, it does what I needed the tablet to do. I miss the 'frontier' nature of the tablets but I don't wanna carry around a bajillion devices. I also think in retrospect, that Nokia really screwed up by not bundling a GPS program that didn't expire. The iPhone GPS is pretty quick (I think it uses cell tower triangulation for it's inital fix) and makes a little blue dot travel along a google map image. I guess that's the bonus, being connected it can DL tiles... but still. The nav software wasn't bad... until the trial ran out half way to our destination. Now GPS is all but useless because I don't have an active data connection unless I'm stationary and on wifi.

All in all, try the iPhone out and see if it suits your needs. If you want a phone that also acts as an internet appliance, give'r. Please be aware that you can't have apps running in the background. If you're running IM+ (a multi-protocol messaging client), you can't leave it on in the background after you lock your phone and chuck it in your pocket or go into another app.)