New carbon nanotube aerogel is now the worlds lightest material

Frozen smoke (read: aerogel) -- not to be confused with the stuff your Grandma uses to flavor her turkey -- is the world's lightest material, and it just keeps getting lighter.

Researchers at the University of Florida have created a new form of the super material, known as multi-walled carbon nanotube (MWCNT) aerogel, that has a density of just four milligrams per cubic centimeter and can be used in sensors to detect pollutants and toxic substanc

Source:
http://www.engadget.com/2011/01/16/carbon-nanotube-aerogel-now-the-worlds-lightest-material/