As of July 2010, I've come to a conclusion that the ultimate meaning of life, for me at least, is to have as much fun, entertainment, as possible. The amount of fun is equal to a definite integral of fun-power over time. The fun-power is never negative, but it is zero before birth and after death.
Why is that? Well, think of what would one do or want to do, if one could live forever and have perfect health all the time and one could just change one's capabilities, mental and physical, to whatever one wants to, except to remove the capabilities changing capability? What's left then? Entertainment and nothing else and the loss of fun and loved people around me would decrease the amount of entertainment. (Loss does not always have to mean death or "destruction". One does lose every-day objects without destroying them.)
So the way to maximize fun is to prolong one's life and to increase the fun-power. People differ in how they try to achieve that. For instance, some find it most efficient to rob or kill or just tease, if no one is capable of dying. Others find it beneficial to have an environment where everyone tries to treat others the way they self want to be treated. The idea being that one can better maximize one's own fun by not attending in a zero-sum like game, where the increase of one's own fun entails a decrease of someone else's fun. So, it takes quite a theory and skill to be happy in a paradise. :-)
Update at 2013_04_27: There exists "The Meaning of life, Version 2".