U.S. foreclosure activity in the first quarter of 2007 was up 35 percent from the first quarter of 2006, according to the RealtyTrac U.S. Foreclosure Market Report released today. The report documents a total of 437,498 foreclosure filings, which include default notices, auction notices and bank repossessions, during the quarter and a quarterly foreclosure rate of one foreclosure filing for every 264 households — the highest quarterly foreclosure rate since RealtyTrac began issuing its report more than two years ago....