I got mine "preserved" at the dry cleaners, so it's in a box in our basement closet. I married in 1998...and I have no daughters (and I'm likely done having kids)...so it's likely just going to stay in the box until I die and my heirs toss it in the trash or something.
If anyone doesn't want to hang on to theirs, and wants to do something useful with it, I like the idea of this organization
http://www.stanthonysbridal.com/St_Anthonys_Bridal_a_501c3_Organization/home.html
I have no personal experience with St. Anthonys--nor do I know anyone who does--I've just heard of it and think it sounds nice.