Mortgage rates plunge: For a few borrowers, 30-year fixed loans under 4%

"Would a 30-year fixed-rate mortgage for less than 4% make you think about refinancing or even buying a home in today's battered housing markets? Home loans at that seemingly hallucinatory rate were out there this week, mortgage industry insiders said Tuesday -- at least for those few gold-plated borrowers willing to fork over king-size upfront discount points and origination fees."