dtla1 linked to my thread.
Pick up a laser level, and some angles from your hardware store. It's the same process as a string alignment, but there's no string to trip over and lasers are cooler than twine
I've used it with good results, combined with an Excel alignment sheet I put together. I've found it difficult to get the steering wheel perfectly centered, but that's all my laziness and "it's good enough"-isms.