Ok, so in the past 18 months i've gone through a Sony Ericsson K810i and K850i, an LG KE970, a Nokia N95 and N810, a Motorola Z8 and a Blackberry Curve. I'm planning on picking up an XPERIA X1 and probably the HTC Touch Pro too, but i got a 3G iPhone just before my trip and it's probably the best phone i've ever had. Granted, it doesn't do video and the photo's are shit, but it does everything else flawlessly. It's important for me to have internet and email access on my phone which is why i bought the N810 and Curve, and while the Curve has proven to be invaluable for me, the iPhone is just in a class of it's own right now.
I nearly bought the original iPhone, but i'm glad i didn't because i would still have bought the 3G version when it came out anyway. I don't know what the score is in the US, but on 02 in the UK data usage is both unlimited and free meaning that i can jump on the net absolutely anywhere and it won't cost me a penny. Ofcourse, i've had several phones with unlimited data plans already but the web browser on the iPhone (and Touch) is by far the best available on any mobile device. The Push e-Mail functionality (which is also available on the Curve) and fact that it supports Microsoft Exchange means that my emails come through instantly and i don't have to carry the Blackberry around with me. In short, i get the best of both world in one device that has a larger feature set than the vast majority of phones. While i do almost always have some sort of bag with me, it'll be nice to be able to leave me apartment with just the iPhone. Obviously it's not exactly life and death, but it's nice not to have to wait while your phone checks whether you have any new mail.
The GPS functionality using Google Maps is cool, but obviously not a replacement for a fully fledged satnav. I suspect i'll use it quite a lot abroad and probably while i'm on foot in the UK, so it'll likely come in handy to have.
I'm slightly disappointed by the lack of user created ringtones and the fact that you can't just use any track; instead having to download them from iTunes for a fee, ...but it's a minor frustration and i rarely have my phone on anything other than vibrate anyway. I'm also slightly annoyed that Apple didn't increase the capacity to match the newer Touches. 16GB is fine i guess, but i would have prefered 32. Again, it's not an actual problem, but it is a slight annoyance.
The user interface is obviously nothing new to any of you guys, especially those of you that already have an iPod Touch, but it's still worth mentioning that it's unrivalled at the moment and i honestly can't see how it could really be improved. iTunes may blow, and OS X may be a serious pain in the ass, but they nailed it for the iPhone/iPod Touch.
I've downloaded a multitude of apps from the App Store and while most of the stuff is a bit meh, i've found the audio phrasebooks to be pretty cool (i need one in Hebrew now) and think Super Monkey Ball is the best version since the Gamecube original - even if it does take some getting used to ;) Even though a lot of the stuff is pretty lame, there's an awful lot of room for development and improvments over some of the current apps (like the Facebook app) and since the App Store allows users to expand the fuctionality of the device, i can't think of any negatives surrounding it.
Battery life is comparable to the Touch when playing video or music, but since i'll primarily use it as a phone that translates into a much longer timescale. Using it as a phone and web browser, it outlasts many of my other phones... so yeah, no complaints.
I don't know if any of you guys have already bought one (Adam? Rampage?) but if not, i'd highly recommend it. It camera sucks and doesn't do video, but other than that the thing is virtually perfect. There are similar phones by LG and Samsung on the market, but neither are actually comparable.
I'd actually be interested to know what kind of phones you guys use, and whether any of you (save for Adam) use mobile devices for internet access and to post here!?