The Trophy Taker is a good example:
Start by looking at this picture:
http://www.trophytaker.com/id264.htm
It has a Y-shaped rest that rotates about an axis. A spring pushes the Y flat against your bow when you're not under draw. A string attached to your cables lifts the Y up when you draw, to support the arrow. Shortly after you release the shot, but before the arrow leaves, the spring pushes the Y down again, and the arrow is totally unsupported, and is just being pushed forward by the string. The fletchings (feathers) can easily clear the Y, because it is out of the way, and you get "easy tuning" as a result.
It might sound like this kind of rest is not accurate, but it is: The Las Vegas Archery Festival was won with one.
The big problem is that you have some mechanical complexity, and it will fail eventually.
The best rest of this type made is the ARE Sniper V, but it is even more complex, sophisticated, and failure prone; so, the TT is an excellent choice.
kgk