Check out this terrific video of Penn & Teller in the Houdini Collection vault at the Library of Congress in Washington, D.C. I love these guys. I also love that we see here the actual "Dear Ma" postcard from Houdini's runaway days (pic below). I've seen this myself, and I've always tried to explain just how surprisingly small the postcard really is. Now you can see for yourself. Enjoy the tour.
By the way, if there's a government shutdown tomorrow, I'll be happy to look after the Houdini collection for free. Just throwing it out there.