The BP oil spill's impact on home values in 15 coastal counties along the Gulf of Mexico could total $3 billion over five years, according to report released today by business information company CoreLogic. An additional $28 billion loss in values could also occur in the unlikely event that oil reaches communities around the Florida Keys and up the Atlantic coast, the report said.The report analyzed the spill's potential effect on home values in one Alabama county (Mobile); one Mississippi county (Harrison); and 13 Florida counties (Bay, Brevard, Broward, Collier, Duval, Escambia, Hillsborough, Lee, Miami-Dade, Monroe, Palm Beach, Pinellas, and Volusia).Specifically, CoreLogic measured the spill's impact on properties' economic value associated with beach access, which the company refers t...