Having used both, the Bold is better for business. If you need to bang out some emails, the tactile keyboard is easier to use. There are less bells and whistles, but what it does it does well. Calls, Contacts, Emails, Tasks. The browser has some short comings and the screen is smaller. But they are relativly durable.
The iphone is a bit more consumer oriented, and has a much better browser interface. (however a lack of flash is still leaves something to be desired. The interface and keyboard do take some ramp up time to get used to (more so than the BB) But it's not a big deal once you use it for awhile.
The iphone wins in the App department right now as well. A broader range of software and yes that includes some great diving programs. with an iphone you are currently stuck on ATT - this can be an issue depending on your location. The BB has a wider selection of carriers.
I had/have used a BB for years and was underwelmed by the storm when it first came out. MY curve (work) is close enough to a bold that there wasn't a reason to upgrade. (But we did demo it and I liked it as much) The iPhone 3g is a 2nd generation phone, so they did get some time to put some fixes into it. There's an update due out mid year so that will add some long awaited features. (and will probably break a few things too!)
If you want something easy - to make calls and read / send email. I'd go BB. If you do a little surfing, and want to add some apps, the iPhone is a little more robust. (I never thought I'd admit it - but I like my iPhone a little better.)
good summary.
I've got the Storm and I will say it's not as "flashy" as they wanted it to be. My impression was that it was "rushed to market" to try to compete with the iPhone before the Christmas buying season.
I chose it over the other BB products because I wanted the larger screen and rarely need to use the keyboard for long periods.
would be cool to have the apps that the I phone has.......
Here are some things that I noticed that are greatly different on the phones, for comparison purposes.
Memory - On the BB Storm, if you want more memory, you simply upgrade your microSD card. (It comes with 8bg and put in what you want. The iPhone the memory is made in and you have to upgrade phones to get more.
Battery - the storm has a replaceable/removable battery. The iPhone does not. (I've already had to replace my battery under warranty).
802.11g - The iPhone supports 802.11g "wifi" if you're accessible to a public wireless router/access point, such as in a hotel or conference center. The BB Storm does not have this feature.
Apps - iPhone beats the BB hands down. But most people for business purposes really only use the BB primarily for email it appears. iPhone users tend to have a bigger spectrum of what they use it for.
Price - the BB Storm is much cheaper than the iPhone (or was when I got mine. I think I paid about $50 or $100 total after a $100 corporate deal credit and $50 mail in rebate).
GPS - the iPhone GPS is incorporated with Google Maps. The BB Storm uses their own app. you also have to pay $10/month to get GPS with Verizon and don't have to pay that with AT&T on the iPhone.
There are other issues and comparisons, but these are jsut a few off the top of my head. hope it helps.
mike