Seems everyone these days is giving the thumbs-up, no matter the circumstances.

Senator Edward Kennedy gave a big thumbs-up as he left the hospital Wednesday, facing a new outlook on life with a potentially deadly brain tumor. Hillary did it just this week at a we're-not-mathematically-defeated-yet campaign rally in Florida. John McCain can't not do it.

The gesture, for better or worse, has long breathed life or death into major events.

Death to gladiators

The thumbs-up gesture has its roots in ancient Rome, where gladiators would literally live or die by it. Pollice verso is the Latin term for the gesture, meaning "with a turned thumb."