I don't know if anybody is interested but if you send an invitation to the President of the United States the White House will usually send a signed plack. My sister did it for her wedding, I thought it was cute. Here's the info if you'd like to have it.
The Honorable Barack Obama and Mrs. Obama
The White House
Greetings Office Rm. 39
1600 Pennsylvania Ave.
Washington, DC 20500
no. 2 by Fax
Wedding invitations to the President can also be faxed to: (202) 395-1232
The White House greetings office handles as many wedding invitation requests as they can. Send your wedding invitation at least six weeks in advance. Be sure to include your old and new mailing address in case the RSVP comes later.