The Antikythera Mechanism — Ancient Greco-Roman clockpunk (thanks again to goulo, for reminding me of this)
Bendable light — nomads making use of nanotech "light batteries"...the applications for this stuff if it were widely available are boggling
Dinosaur skin fossils
Steampunk computer mouse — please sire, may I have
ETA: martang sends this video of the Kaye Effect. Fascinating video, and further examination proves that tdj makes a lot of very cool science, technology and culture posts.