Here's a tip for all you soon-to-be-centenarians out there: If you want to make headlines, have a good answer locked and loaded for the secret to your longevity. Not something boring like love and happiness; something wild and fun. Examples that have worked in the past: a daily Guinness, Hershey's chocolate, and Johnnie Walker. (Another tip: Plugging a specific brand is a good way to get free stuff!) Of course, Betty White – who turns 100 on January 17 – doesn't need any help making headlines. And clearly, the lifelong actress knows a thing or two about entertaining answers for...