There's an org that collects and resells formal dresses to benefit breast cancer awareness. Not sure of the name, but there is a local gal who is (or used to be) on these forums who was one of the directors of it.
Just saw a pay on FB that an organization called the Blue Dess something is collecting donations. They have several local locations. I'll double check the exact name.
Edit: drop off locations are at Marrick Homed model homes. Contact Lynn Smithburger 443-975-4424