Okay - this might not be the most practical use of nixie technology but it is cool. They are attendance badges based off on IN-16 tubes and powered by only two AA batteries which provide a shocking 40 hours of life. Be sure to check out the links below for much more information.
Konstantin from Kosbo.com has a new board for IN-18 and IN-14 nixie tubes for sale on eBay. It is the diameter of a tube and includes the high voltage transistors and resistors needed in one nice package. For 2.99 GBP, it is a pretty good deal.
(images and text used with permission)
Okay, we're a little late in covering this one; Hack A Day and Engadget beat us to it. This is a 81-Nixie tube based Sudoku board which appears to use IN-12's (based on the upside down 2 used as a 5.) There are two knobs on the board, one controls the x position and the other controls the y position of the cursor. The number pad controls the actual value of the input. Be sure to visit the site - he graciously includes the source code and schematics.
eBay seller Turbo_Mac has a few new gadgets up for sale. One of them, strictly speaking, isn't a clock at all but it is an EM84 "magic eye" tube that he has re purposed as a a VU meter. The device has both an internal microphone and as line-in (not in a mini plug connector, however) to control the display. Bidding starts at $1 and ends in 7 days.
This is a fully assembled 6E2 (EM84 equivalent) VU meter that accepts both line-in and on-board mic signal. Its glowing bars close while audio input is strong, and open while it is weak. They're like naughty jumping elves! The continues patterns provide ultra fast response than any other VU meter! Please refer to the video below or contact me for other details.