This barcode clock uses code from:
base2 - A standards-based JavaScript Library.
Code128 - Free JavaScript implementation of Code128.
setTimeout and Firefox... - padTime() came from padZ() in this forum post.

There is a short version with the :'s removed from the barcode and a unix time version.

August 21 2010: There are now QR Code and unix QR Code versions that use the PHP QR Code library.