Cathode Corner sells this handsome, motion-activated Nixie-tube wristwatch for $395 — despite its baroque, fragile appearance, it’s billed as “rugged and water-resistant.” The motion-activation looks pretty slick: when you roll your wrist up to look at your watch the hours and then the minutes light up in the two Nixies in the watch. The firmware is GPLed and can be freely hacked, too.
(Thanks, Betsy!)