Andersen Levelers?

/\ Actually the Anderson levelers work much better than a simple wedge. Check them out on you tube. The contour of both wedges work together to allow for more secure chalking (basically locking the wheel in place by working together) and they're wider as well. It's also easier to get up on them because they roll with the tire. Much easier than just pulling up on 2X's or a wedge.
I have a set and they work great for our TT.