Telemarketers, vendors and people I'd rather not communicate with frequently intrude on my early morning slumber (esp East Coast vendors), meetings, lunches, free time and life in general. And since they usually call from unrecognized numbers, I feel compelled to answer (could be something important, right?) A co-worker and I have been using a neat technique to remove these individuals ability to communicate with us...create a new contact called "Do Not Answer" with a custom silent ring tone. Each time they call from a new number, add them as an additional number to that contact. And with that silent ring, now they can't interrupt you in meetings, at home, early in the morning, etc.
I used iTunes to make a silent ringtone...you can download it here: iPhone Silent Ringone