Robin, as this is an iPhone blogsite/fansite, you should expect to see comments mostly preferring the iPhone. If you post the same question at Crackberry.com (you may have as I didn't check), I suspect the responses will be quite different.
I am a long time BB user (BES) and a year long iPhone admirer. I consider myself as fairly impartial on the subject of iPhone vs. BB.
I currently have a Curve 8310 and I absolutely love the device. Push e-mail, phone features, contact list, calendar, and to do list all work perfectly. What's better is that it and my office PC sync to each other OTA perfectly. But I must add that I am a BES customer and my company pays for the service. I know the service fee for BES is quite expensive and I can’t vouch if being a BIS customer will have the same quality of service as I currently have.
I also love the Curve for one more function and this is something the iPhone can't do. The Curve can double as my mass storage device. I can download podcasts from any computer and listen to them during my commute. No iTune required and no worries about erasing my music files on my Curve by syncing to an iTune with the wrong library. I also store lots of pictures of my kids on my Curve and upload them to my parents' PC when I visit them. Finally, don't believe it when people say that BB has a high learning curve. The Curve is just incredibly easy to use and so versatile and functional. If there was no iPhone in this world, the Curve will hands down be the best smartphone, IMO.
But then I saw the iPhone in the Apple store, and I instantly felt in love with its form factor, its big and beautiful display, its touch interface, and its full HTML web browsing capability. It is such a media powerhouse and so hard to not like this wonderful piece of gorgeous hardware.
That said, the iPhone has its limitations but many people are able to tolerate them. First and foremost to me, the virtual keyboard takes alot to get used to. I play around with my co-workers' iPhone all the time and I still have trouble typing half as fast as on my Curve. Secondly, it does not have a removable battery. If you are often on the road for extended periods of time, a fully charged iPhone will not last you the entire day. To have spare batteries to fall back on would be nice. You can get aftermarket battery sleeves that attach onto the iPhone, but it makes the phone bulky and Apple shouldn't have forced its customer to do that. Thirdly, the iPhone does not support external memory cards which is a shame. I find external memory cards a very convenient way of swapping large media files while not taking up valuable drive space.
At the end, both BB and the iPhone are phenomenal smartphones. I don’t think you can go wrong with either decision. The BB works well and is a productivity demon while the iPhone is just so beautiful to look at and operate that you give in to its limitations. I decided that I must have both devices so I am keeping my Curve and my wife will get the 3G iPhone, best of both worlds.
Wow, sorry for such a long post. I guess I had a lot to share.