I haven’t been able to verify this at all, but if it’s true it might be the Best Science Fair Project Ever. Ten-year-old (at the time) William T. Wood, fresh from his 2002 science fair win for a project on silica aerogels, he decided to kick it up a notch and see if silica aerogels could be made at home. And by "made at home", I mean "without the really expensive equipment previously thought to be essential."
Fortunately a newer method allows for supercritical drying with liquid carbon dioxide. […] Nevertheless it seems not to have been previously tried because of the need to carefully control and maintain both pressures and temperatures for 10 to over 100 hours, depending on the thickness of the aerogels being made.
After studying the problem for a full year, William found a simple but elegant way to substitute human attention for expensive laboratory equipment. He would use the thermal properties of water to control the temperature and a hand-operated needle valve to control the pressure and liquid flow.
With the budgetary constraints facing a fifth-grader, William settled on modest ambitions. His homemade aerogels would not be large. […] This gave a maximum size for the aerogels of about 1-1/2" by 5-1/2", and (for time constraints) about 1 centimeter thick.
The article goes into great detail, enough for a handy GeekDad to use as a how-to. The process is based on one listed at the Lawrence Berkeley Laboratories, with enough notes and modifications and tips to give the strong impression that this really did happen, and successfully. So, who’s going to be the first to try this out?
(Note: if you aren’t sure why silica aerogels are completely awesome, be sure to read the Times Online overview article about aerogel applications.)