Running a Contest or Event:
Apply at http://defcne.net/! Contact Pyr0 at pyr0 at defcon dot org to inquire about running a new contest or if you currently organize one and have questions.
(Note: For info on the individual contests themselves, check this thread on the DEF CON Forums.)
Being a Vendor:
Read the Vendor FAQ at https://defcon.hackingyour.net, then fill out the application. Direct any questions to chris at defcon.org
Registering as Press:
Apply to press at defcon.org
Being a Speaker:
Answer the Call for Papers!
Being a DJ and/or Band:
Answer the Call for Music, posted on the DEF CON Forums. Contact person is DJ Great Scott at dcxxmusic at gmail dot com.
Getting in touch with Dark Tangent:
DT's contact info and public key can be found here.
Website and Program Submissions:
Submit updates for the website or material for the printed program to Neil at neil at defcon dot org. Anything to be published in the printed program is due June 8, 2012.
Neil's GPG Fingerprint: A29E A7F9 C1AC 6AD4 FD68 96C7 BCB5 73B6 1A2C 61A3
Neil's Public Key