SBaugh: I've searched the help; all it says is that you CAN do it, not HOW. I've created different configurations. When I mate two part faces to be a certain distance there is no option to make it configuration specific. Even after I've made the mate and right click on it and select Edit Definition, no configuration option. If I right click and choose properties, the only configuration option I get is to supress it.
I just figured out how to do it. For some reason you are not allowed to specify configurations of mates in the "Edit Definition" like other things. If you double click the mate and change it that way, the option to specify the configuration will be there. Thanks everyone for your help.