Most of the time I get multiple calls with no one at the end of the phone. A guy with a very sleazy voice acted like he was flirting with me. He said something like Hi.....How are you doing? And I hung up the phone. When he called back, I never answered. There was no number or way to find the number. It just says out of area. Today I got 4 calls in a row, and the second one had this number: 406-720-2882. I never said anything and the person then hung up. They immediately called back twice more with no number, and I answered and hung up. A search on the number shows alt.atheism & alt.agnosticism
I got two calls from this number in one day. It is a computer dialer for ER Surveys. One was a female and one was an overly friendly male. They wanted to ask questions of people from 45-65. I hung up on the first one and told the second to never call again. I intend to complain to the nocall.gov list. Sometimes this stops the calls.