Nixie tubes are the absolute eye-catching displays. The guy form bildr had some nixie tubes, and he wanted to make a project that would be for his sirte and, if possible, connect to the internet. These specifications lead him into the nixie twitter counter!
He used the Arduino Pro 328 from sparkfun along with the Wiznet Ethernet shield w5100 to get the data form the net. Nixies needs of a special high-voltage driver to operate. He used an open source stackable driver from ogi-lumen for the job, suitable to be used with arduino, along with an DC-DC converter to supply the 170volts needed (from the same company). Check out his site for details about this project.