What the heck is gravity?

LiveScience.com has posted a good article on one of the great mysteries of physics. What is gravity? It's considered one of the four forces in the Standard Model of physics, but it's the one that refuses to "play nice" and fit into models. The Einsteinian universe accounts for gravity on large scales (like the gravity of planets, asteroids, or human beings), but breaks down on the subatomic scale. Some physicists look for particles called gravitons. Others search for gravity waves. None really understand the force that binds the universe together (as Yoda would say).