I bought an old Edison cylinder from a customer at the shop today. They're not worth anything (with some exceptions), but as a curiosity and a conversation piece it has value. I still marvel at the technology.
if you guys REALLY want to GEEK OUT, you must read this wikipedia entry about the history of recorded sound PRIOR to Edison's experiments with his wax cylinder machine. Seems they were recording sound long before anyone had ever even contemplated playing it back. http://en.wikipedia.org/wiki/Phonautograph