Do not get the touch screens from Blackberry, just not their forte.
The Blackberry or iPhone, it's actually a very simple decision. Each one caters specifically to the needs of their different users.
Blackberry's: great for those who just want a phone to talk, text, e-mail, BBM (chat), web-browsing.
iPhones: fun, tonnes of apps to play around with, etc.
I personally go with the Blackberry because I want my cell phone to be a cell phone, not an entertainment unit. I see the iPhone as an fun gadget with tonnes of apps which also have phone and texting capabilities, as opposed to a smartphone primarily... Vice versa for the Blackberry