I was looking for a auto-rig script for 3ds max and I found this great script called Super Simple Rig, from SuperRune.
The Pros are that is that the script is really solid and well done, and the rig includes eyes and jaw by default (though you can remove them from your setup if you don't need them). With a click of a button you can create a rig and deleted if you don't like it. It uses locators to setup the bones and the PEN attribute holder script is present in all the controllers, which is a nice way to create pose libraries. And it's free.
On the Cons side, the fingers are a bit hard to setup, since the script does not take into consideration the rotations of the locators (so the orientation axis of the controllers is calculated by the position of all the related locators). In addition, the setup options for the spine are different from what I have seen so far, and there is no option for IK/FK spine control (there is one but the IK and FK are active at the same time).
There are not a whole lot of rigging scripts out there for 3ds max (not really needed since there is CAT and Puppetshop), but if you're looking for some additional customization, give it a try. You won't be disappointed.