Folks, Here is our experience. My wife and I passed our Naturalization interview and got our oath letter same day for Nov 19 th 2008.
Chicago DO office is on 101 Congress Parkway. There is cheap parking on intersection of Clark and Polk St. $14 for all day. Can come and go out any time. We got there at 12:40 for a 1:15 interview. Parked our car. Went through security. We had our kids with us.