Space Shuttle Endeavour's On-Board Souvenir Stash
Robert Pearlman writes: "Seven astronauts, four payloads, and over 11,000 souvenirs are on their way to the International Space Station, among them a U.S. flag recovered from the World Trade Center, a cylinder record which belonged to inventor Thomas Edison, and golf course markers from Scotland and Ireland. Read the entire manifest here."
The "Meatball" is NASA's internal slang term for the version of their logo with the blue ball.
http://www.nasa.gov/images/hotnasa.gif
But the prime cargo are the larger items in the payload bay, followed by the astronauts. So, you might as well stuff every nook and cranny aboard that orbiter -- as its going to launch regardless (a.k.a. there are no savings for lighter cargo)