Amtrak today begins its fall "Explore America Fares," offering round-trip travel in any one region for $179, two adjacent regions for $239 and the entire U.S. for $299. They're good for travel through Dec. 16. Call (800) USA-RAIL. . . . Apparently, suspected smugglers are very health conscious. Patrick Jones, spokesman for the U.S. Customs Service in Washington, D.C., says he's "amazed at how many people would rather be frisked than X-rayed" by new "body scanners" being tested in Miami and New York airports on people under suspicion of carrying drugs or other contraband.