I found out about this project when Cori posted about it a couple weeks ago: Jen of Miles & Blessing homeschools her daughters and is currently working on learning about the states. Since she (and her daughters!) run, she's putting together a bulletin board of postcards from runners in every state.
Finally mailed them my postcard last weekend:
If you want to join their project, send Jen an email at jensrunning26 at gmail.com.