I would sync with your computer using your blackberry. Then sync the iphone.
Did you finally get a iphone?
Do you have outlook or outlook express on your computer? That's how I moved mine from my BlackBerry to my iPhone, it was the easiest way for me. Just set iTunes to use outlook for contacts (and Calendar if you use it) like Txdogs explained. It is the same with a PC, just select what you want iTunes to sync to.
This is the way I transferd from my blackberry to iphone.