The average rate on 15-year fixed loans, a popular choice for refinancing, fell to 3.57 percent from 3.63 percent, Freddie Mac said — the lowest since the survey began in 1991. The average rate for 30-year fixed loans fell to 4.17 percent from 4.24 percent last week. That’s the lowest on records dating to 1971.

http://www.boston.com/realestate/news/articles/2010/11/12/mortgage_rates_continue_record_slide/