The Chronotheric Fluxing Capacitron is a lovely steampunk gadget that crackles with blue light, appearing to be some kind of time-travel thinggum. Flickr use Absinthetic notes that it was a "prop to accompany my Halloween 2007 costume, which was a 19th century time traveler."
(Thanks, R!)
Update: The creator's weighed in on the comment thread with a link to an earlier version