Was it back in 1999 that I put the first Nixie Tube clock on the web? It's been a popular page over the years. Amazingly, the Wi-Fi Safari web browser in the new iPod touch (iPhone too) displays that old nixie clock web page just fine (photo below):
Try this optimized version of an iPod Nixie Tube clock on your iPod (photo below):
So there it is: a 2×4×¼ inch Nixie Clock. Links for the iPod clocks are on my mobile page: http://LeapSecond.com/m
Of course, the right way to do this is wait for Apple's iPod dev kit to be released and write a native plugin, but until then this browser-based nixie clock does the job.