Folks, Chu is the Secretary of Energy, not Treasury. See http://en.wikipedia.org/wiki/Steven_Chu.

Our annual survey of the Internet's DNS infrastructure measures (among other things) the percentage of a random sample of com, net and org subzones that use SPF. In the October 2009 survey, we found that 12.2% of the sample used SPF records. For more information, see http://dns.measurement-factory.com/surveys/200910.html