The Chumby version of the Life-O-Meter has alternately been described as "the most depressing thing ever" and "inspiring".
Operation is simple. It's just a little widget that stores your birth-date and the amount of years you expect to live (defaulting to 80), and it displays how much of your life is over. What you do with that knowledge is up to you. Hopefully it will inspire you to get working on those "bucket-list" items you've been putting off.