I got to fondle some ceramic bearinged Phils at the NAHBS. Imagine holding the axle with your left hand, and spinning the hub with your right. Then imagine it spinning and spinning and spinning. There's no lube in there, and right little friction either. I think the races are specially hardened steel, and the ceramic balls are, well, really hard, so they last forever.
They cost upwards of $9000 each.*










*That is a lie.