This is a native stonecrop with long slender toothed leaves in a spiral formation.
Each stem is topped with a yellow cluster of starry blooms. It's often used as a green roof plant, or in rockeries and containers. Still in the research and development phase of testing here in my xeric garden - more information to follow.
Update; May 2013: Still waiting to see how this tiny little guy will do; I'm sure once it's established, it will take off.