Regarding the 9/12 crowd size...

The MSM continues to repeat the “tens of thousands” estimate, despite numerous reports from people who attended that this estimate is woefully inaccurate.  For some reason there has been a conspicuous lack of arial photography to either confirm or discredit this estimate.

Fortunately, Constitutionally Speaking (http://constitutionallyspeaking.wordpress.com/) seems to have been able to dig one up.  Scroll down a bit, I’m not allowed to upload media =).
Compare it to this arial of January 20, 2009: http://www.talkingpointsmemo.com/images/obamainaug-blog.jpg.

USA Today was helpful enough to provide the system by which the NPS estimates crowd size on the National Mall: http://www.usatoday.com/news/washington/2009-01-19-crowd_N.htm

MSM still sticking to “tens of thousands.”   Hmm…

Also, a very good write-up by Charlie Martin at Pajamas Media: http://pajamasmedia.com/blog/how-big-was-the-crowd/