I am the chairperson of a Chicago Suburban project that stemmed from volunteer realtionships with the Glass Slipper Project of Chicago. Currently Cinderella's closet is a project of the Junior League of Kane & DuPage Coutnies, Inc.
These programs would be an ideal place to not only donate your clothing and prom items but for greek voluntarism opportunities.
I can assist organizations interested in working to set up programs.
http://www.cinderellascloset.info/