I went to MTV's site in hopes of getting a ticket to this Friday's show which will have the entire Lord of the Rings cast and sadly found out that I'm too OLD to attend:
Here's the information from MTV.com F.A.Q.
How can I get tickets for TRL?
If you are planning on visiting New York and want to be part of the studio audience, call the TRL hotline at (212) 398-8549. You must be between the ages of 18 and 24. [More]