Instructables user mrfixits just posted this su-wheet luminiferous aetheric Tesla-punk tranceive-o-mogrifier doo-dad build. He explains it rather better than I:
The Spooky Tesla Spirit Radio is a crystal radio circuit in a jam-jar. It makes fun spooky sounds by responding to input from several types of electromagnetic sources. This non-powered radio plugs right into the computer sound-in jack, and makes use of audio software for real time sound effects.