California!
http://www.sos.ca.gov/elections/elections_faq.htm
They do an inquiry with the DMV but don't need verification for registration, eventually they stick your name on the registration lists.
When I voted in person, not absentee, I was able to walk in to my polling place state my name, receive my ballot and vote. No ID cards needed, pretty awesome. More states should adopt this type of registration, more voters.
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Do I need a California driver license or California identification card to apply online? What happens if the Department of Motor Vehicles does not have my signature on file when I try to submit an application online?
All Californians who are eligible to vote may fill out a
voter registration applicationthrough the Secretary of State's website. California
military and overseas votersmay also use the Secretary of State's website to fill out a voter registration application and request a special absentee ballot. If you do not have a California driver license or identification card number but you enter your other information, the website will create a pre-filled voter registration application for you to print, sign, and mail. All of your information will be sent directly to your
county elections office so that when your signed application arrives in the mail, the county elections staff will simply add your signature to your voter registration record.