There's a remarkable amount of worldwide interest in the uncontrolled re-entry of the Upper Atmosphere Research Satellite, given the infinitesimally small risk. Here's the awkward beast:
For near-Earth-orbit fans, here's a link to my 1999 article for Smithsonian on space debris. It was a fun article to research, and it got me into the NORAD command center in Cheyenne Mountain, Colorado, among many other unique spots. (Sorry, public tours into the mountain are yet another casualty of 9/11.)
According to this AP article, NASA owns every bolt, nut and shred of UARS, so don't think about putting the tank or thrust chamber you find on eBay. (As you can see from the photos on this site, tanks, particularly titanium-walled pressure tanks, have a pretty good chance of surviving the heat of re-entry.) Here's one:
The most famous pieces of American space wreckage derive from the loss of the orbiters Challenger (1986) and Columbia (2003).
Less than a year after the disaster, NASA sealed all pieces of Challenger into two decommissioned missile silos at Cape Canaveral Air Force Station's Launch Complex 31. Here's a NASA photo of Challenger wreckage being put away:
But not all of Challenger went in there, because not all of it was found. A critical piece of the shuttle's right-hand booster was never located, and almost eleven years later three pieces of Challenger washed up on a beach in close proximity, one nearly 13 feet long.
NASA collected and siloed them as well:
This website at CollectSpace.com hosted a discussion in 2007 about what NASA should do with such historic pieces.
What about remnants from the first American spacecraft disaster, the oxygen fire in the Apollo 204 command module that killed three astronauts in 1967? At last report, the singed capsule is in storage at Langley Research Center. While the item has never been displayed in a museum, it is more accessible than are the remnants of Challenger.