Shh, don't tell anyone, but in two days, I'm driving south to Mexico Beach, FL, a little community on the Panhandle, 30 miles east of Panama City.  I've rented a house for two weeks (for $300/wk). It's the third time in 4 years I've done this--a getaway from Indiana winter and my boring daily routines. It's a wonderful retreat. The beaches are spectacular and virtually empty. No malls, golf cours…