It is estimated 3,000 at the Overland Park, KS Tea Party.
I heard on the radio tonight that as many as 7,500 were estimated at the Liberty Memorial in Kansas City, MO.
Here are estimates from local media.
http://www.kmbc.com/money/19187153/detail.html
Lee’s Summit, MO 300 people
Liberty Memorial, Kansas City, MO 3,000 people
Overland Park, KS (Johnson Co. Comm College) 10,000 people
I saw a Freeper Report Ottawa, KS (my small hometown) 70 people