Dr. Pepper was invented in Waco, Texas, and we've got the Dr. Pepper Museum to prove it.  Located inside an historical building in downtown Waco.  The lower level has an old-fashioned soda fountain, museum exhibits and a gift shop.  We tried Dr. Pepper floats made with vanilla ice cream, which were delicious and not terribly expensive.Exhibits are $6 for adults, $4 for senior...