IL Voter Registration Deadline is Tuesday, October 7 - Psych - There's a Two-Week Grace Period
Monday October 6, 2008
Officially, you need to get your tardy vote-registering butt down to your local county clerk's office by tomorrow, Tuesday, October 7. Lucky for you, though, the entire state has a two-week registration grace period that runs through Tuesday, October 21, 2008 for the Tuesday, November 4, 2008 general election. Below you can find resources on how to register to vote in Cook County using the grace period. If you live outside of Cook County, you'll need to contact your local county clerk's office to find out how to register during the grace period.
PLEASE NOTE: The grace period article was updated on October 8 to reflect that you can now register at one of six places during the grace period. If you read the article when there was only one place to vote, that is no longer correct.
PLEASE NOTE: The grace period article was updated on October 8 to reflect that you can now register at one of six places during the grace period. If you read the article when there was only one place to vote, that is no longer correct.

Comments
The Cook County Clerk’s office only handles voting for suburban Cook County.
Voting in the City of Chicago is administered by the Chicago Board of Election Commissioners. City residents cannot vote at the Clerk’s offices. They must go to the Board of Election Commissioners’ offices at 69 W Washington, Suite 600.
http://www.chicagoelections.com/page.php?id=14