Government and university websites are not very keen to post Google ads, for obvious reasons. They are not looking to make a few bucks off advertising to help cover their operating costs. That’s what taxpayers are for! 😉 Plus it would erode their credibility to do so. However, a number of these organizations I bet would be interested in posting public service announcements, so why couldn’t Google evolve AdSense into something that allowed .gov’s and .edu’s to post contextually-relevant public service ads without any risk of a commercial message sneaking in there?