Back in the early days of BlackBerry devices, when they were basically enhanced pagers that could get your email, they didn’t function as phones. I used to carry a mobile phone and a BlackBerry, using the phone for voice calls and the BlackBerry for email.
But then they put a mobile phone — a good one — into the BlackBerry. My address book and calendar are synchronized with the BlackBerry, and it’s great to have everything on one device. I haven’t had a separate phone since then.
I can’t tell you, though, how often I see someone looking something up in his BlackBerry, and then pulling out his cell phone and calling someone on it. Why? What possible advantage is there to carrying both?