On a lark last spring, Ronald Grant decided to "list" his South Pasadena house for sale on the popular real estate valuation website Zillow.com.Zillow estimated his home's worth at $1.4 million. But Grant, who was planning to sell his home when he retired in two years, decided to have some fun. So he posted a notice on the site saying he would gladly hand over the keys to anyone willing to pay him $1.6 million for his 4,500-square-foot abode.