iPhone v BlackBerry is relatively easy, unless you're looking at one of the Torch models that tries to be a little more iPhone/Android-like, but in reality is way off as there are simply far too few apps, or apps that you'd expect to get on other platforms.
BlackBerry is great for email, and there are some good tariffs that include email, web etc. Things like Facebook, LinkedIn and Twitter can all places updates, private messages and alerts in your unified inbox. The keyboard on the Bold 9900 is second-to-none (the best keyboard I've ever used on any phone, including landscape folding/slide-out smartphones) and since the latest firmware update, the battery is actually quite good.
The Bold (and to a lesser extent the Curve models) is also great for making calls and texting.
And the iPhone is the opposite. Not great for making calls, a bit tricky for texting and emailing as the virtual keyboard is quite small given the tiny (by today's standards) 3.5-inch screen. Amazing display though with 340-odd DPI, and the battery is quite good too. But you have apps and games, which are probably still better than Android (in terms of overall choice).
Personally, it's not a comparison where I'd make a choice as I have a Bold 9900 for work email and social networking, and an Android phone (or three) for day-to-day use. I then have an older iPhone and the iPod touch for iOS stuff - but they don't go out of the house (home office in fact).
I wasn't a touchscreen fan for a while, even using touchscreen devices over 10 years ago - but with a stylus. Back when you had resistive screens, entering text or dialling numbers was hard as it needed pressure and forget the nice kinetic scrolling we now have. Since we got the new touchscreens, I've become a bit of a convert. Even the Bold 9900 has touch, although it hardly needs to.
Anyway, I've waffled on long enough (what was the question again?

) so ask me another question !!