Taken from Defcon.org...

PhreakNIC v5.0-
November 2-4, 2001, and is Nashville's FREE annual hacker con, sponsored by the hacker group se2600.

Bincon-
March 22nd-24th, 2002 at the Alexis Park in Las Vegas.

Rubi-con-
April 5th-7th, 2002 at the Romulus Marriot in Romulus, Michigan.

I'm sure there alot more conventions around...just do a search on google.com. Also you can attend a 2600 meeting once a month if you have one near you.