I absolutely love my iphone, had it 6 months now and still pick it up every time I have a spare minute just like the first week with any new tech.
I'll concede the keyboard isn't as efficient as somebody who can go crazy on a full qwerty keyboard but that doesn't really bother me.
Once it is jailbroken the sky is the limit with all it's possibilities, I think the only thing I've not rectified from the iphones stock flaws is the camera, being only 2mp, other than that I find email, internet, texting and use a breeze.
Both my parents have Blackberrys and had to play with the to teach them how to use them, the pearl I hated but does exactly what it says on the tin, email, phone text, the Bold I prefer and I'm blown away by the screen quality but lack of wifi is a pain in the ass.
For me, neither can touch the iphone for functionality, does everything a blackberry can do and more but depends what you want in a phone really.
If the basics are all you're after then I'll prob concede there isn't a lot between them.
For once, Apple don't lie on their new commercial when they say there is an app for everything, especially if you jailbreak.