Attach your iPhone to your MAC using data cable provided with the phone. Once connection is established, iTunes will launch automatically. Open iTunes.
On the left side of your iTunes window, you will see your iPhone listed. Click on the iPhone and then look on the upper right side of screen, you will see “info” tab there. Click on the “info” tab.
Scroll down; you will see an option to “sync Contacts”. Select that option and press sync button present on the bottom left corner of iTunes screen. It will prompt you that if you want to replace the contacts or merge those, select merge option.
Now iTunes will sync your contacts with your Mac’s address book. Once sync is finished click “Apply” button present in iTunes. Now remove your iPhone from Mac.
Install Blackberry desktop manager software on your Mac, “Download” it and install it. Once you have it, attach your Blackberry phone with your Mac and Blackberry desktop manager software will automatically popup.
In the software you will be presented with list of options to manage your phone on the left hand side. Click on contacts, and after that click on sync contacts from the right side of pan. Now click on the sync button present on the top right corner of your desktop manager software. The software will present you an option to replace or merge the contacts. Select merging option to avoid losing any of the contact details.
Your Blackberry will now be synchronized with your Mac’s address book and all of your iPhone contacts will be copied in your Blackberry.