Aug 9, 2008
Me too. Three or four times a day, late afternoon and evening. Started a couple of days ago.
My guess is it a politician who's subscribed to a repertory dialer service. They place automated calls to hundreds of numbers. When and if you answer, the dialer tries to connect you with a recorded message or a live person. If the recorder or person is not available you get dead air and they keep you on the list to keep trying.
Qwest and others offer this "service" for pay.
If it is a politician, this should cease on August 19th, the day of the primary election. However, expect it to start again a few weeks before the general election.