There is an entire thread dedicated to a much needed application - one that sends categories of incoming callers directly to voicemail. The idea is that during working hours people might want to send contacts categorized as "personal" to voicemail, and on vacation people want to send "business" contacts to voicemail. As it stands there are only highly imperfect approaches to this problem.

Here is the thread:

It occurs to me that developers may not have noticed our cry for help because of the thread's mundane name. So I am starting a new one here. Any developers out there want to take a crack at this one? There are lots of people who would pay for this one.