For those of you wondering, here are the voter registration deadlines for every state (for the general election):
http://www.washingtonmonthly.com/archives/individual/2008_09/014608.php
Voter Registration Deadlines
The election is Tuesday, Nov. 4.
Alabama: "Voter registration is closed for the ten (10) days before an election." By my count, that means that the deadline is Oct. 25.
Alaska: Oct. 5
Arizona: Oct. 6 at midnight
Arkansas: Oct. 6
California: October 20 2008
Colorado (pdf): Oct. 6
Connecticut: "up to the 7th day before the election." By my count, this is Tues., Oct. 28.
Delaware: Oct. 11
Florida: Oct. 6
Georgia: October 6
Hawaii: Oct. 6
Idaho: Oct. 10, but election day registration is also available.
Illinois (pdf): Oct. 7, though something called "Grace Period Registration" is also possible Oct. 8 - 21. Grace Period Registration is described here (also pdf).
Indiana: Oct. 6
Iowa: 10 days before the election. By my count, this is Oct. 25. Election day registration also available.
Kansas: 15th day before the election. By my count, this is Oct. 20.
Kentucky: Oct. 6
Louisiana: Oct. 6
Maine: deadline to register by mail is Oct. 14. No deadline to register in person. Call to see whether you can turn in forms other people have completed in person after Oct. 14.
Maryland (pdf): Oct. 14
Massachusetts: 20 days before the election. By my count, this is Oct. 15.
Michigan (pdf): Oct. 6
Minnesota: Oct. 14. Election day registration available.
Mississippi: 30 days before election. By my count, this is Oct. 5.
Missouri: Fourth Wednesday prior to the election. By my count, this is Oct. 8.
Montana: Oct. 6. Late registration (must be done in county election office) available through close of polls.
Nebraska (pdf): Oct. 17. Registration in person available through Oct. 24.
Nevada: Oct. 4 to register by mail; Oct. 14 to register in person.
New Hampshire: Oct. 25. Election day voting available.
New Jersey: 21 days prior to election. By my count, this is Oct. 14.
New Mexico: 28 days prior to election. By my count, this is Oct. 7.
New York: Oct. 10
North Carolina: 25 days before the election. By my count, this is Oct. 10. In person registration and voting available 19-3 days before election.
North Dakota: does not have voter registration.
Ohio (pdf): Oct. 6
Oklahoma: Oct. 10
Oregon: Oct. 14
Pennsylvania: Oct. 6
Rhode Island: 30 days before election. By my count, this is Oct. 5.
South Carolina (pdf): Oct. 4
South Dakota: Oct. 20
Tennessee (pdf): Oct. 6
Texas: Oct. 6
Utah: 30 days before the election (by my count, Oct. 5); in person registration available through Oct. 20.
Vermont: Oct. 29
Virginia: 29 days before election. By my count, this is Oct. 6.
Washington: Oct. 4 for online and mail-in registration; voters not currently registered in Washington State can register in person through Oct. 20.
Washington DC: Oct. 6
West Virginia: Oct. 14
Wisconsin: by mail, Oct. 15; in person, through Nov. 3; election day registration available.
Wyoming (pdf): Oct. 6