A new stabilizer called "Lock & Load" was updated to 1.0.4 today. It purports to be the world's fastest and more intelligent than SmoothCam, the free stabilizer that comes with FCP, but Lock & Load is $149.00. There's a video of it in action and a free 15 day trial (with water mark) here.
I haven't tried it yet. If I do I'll report back here. It may be fun to run a comparison of the two on the same footage.