Former Vice President Al Gore and his wife Tipper, have been house hunting in Nashville expressing interest in a Belle Meade home appraised at 1.2 million, sources say.Rusty Moore, who owns the 312 Lynwood Blvd. home says that the house isn't officially on the market but that he and his wife have authorized neighbor and realtor Shirley Zeitlin to show it to prospective buyers.Zeitlin, who is said to have shown the house to the Gores recently, was on vacation in the Carribean island of Sr. Martin this week and couldn't be reached for comment.