Comment NIST announced a smaller version in 2004 (Score 2, Informative) 134
Here's the press release
http://www.nist.gov/public_affairs/releases/miniclock.cfm
http://tf.nist.gov/ofm/smallclock/CSAC.html
The 2011 version is comparatively huge --
http://www.smartertechnology.com/images/stories/rcjAtomicClockChip.jpg
http://tf.nist.gov/ofm/smallclock/CSAC_files/shapeimage_6.png