Nixie Clock
The Nixie Clock uses the Make Controller’s Ethernet capabilities to go online and check what the time is, via a protocol called NTP (Network Time Protocol). Once it determines the current time, it uses the digital outs on the Make Controller to communicate with a pair of custom circuit boards that drives the nixies and updates the time.
   Nixie Clock
More detail on Nixie Clock website
www.makingthings.com