My buddy Rick has discovered the virtues of turning notifications on email and BlackBerry off. In fact, he's manually configuring alerts, now, on a person by person basis so he can be notified when really important calls come in.
It's a great idea, and I've been doing it manually for a while too. Imagine if you could do that automatically based on criteria like what you were doing, and where you were… Not that I have any opinions about that sort of thing.
Look for it in an upcoming release of Talk-Now.