The new PS3 software update includes a change to the Terms of Service. The new agreement states that you waive the right to ever sue Sony in a class-action lawsuit, then says:
RIGHT TO OPT OUT OF BINDING ARBITRATION AND CLASS ACTION WAIVER WITHIN 30 DAYS. IF YOU DO NOT WISH TO BE BOUND BY THE BINDING ARBITRATION AND CLASS ACTION WAIVER IN THIS SECTION 15, YOU MUST NOTIFY SNEI IN WRITING WITHIN 30 DAYS OF THE DATE THAT YOU ACCEPT THIS AGREEMENT. YOUR WRITTEN NOTIFICATION MUST BE MAILED TO 6080 CENTER DRIVE, 10 TH FLOOR, LOS ANGELES, CA 90045, ATTN: LEGAL DEPARTMENT/ARBITRATION AND MUST INCLUDE: (1) YOUR NAME, (2) YOUR ADDRESS, (3) YOUR PSN ACCOUNT NUMBER, IF YOU HAVE ONE, AND (4) A CLEAR STATEMENT THAT YOU DO NOT WISH TO RESOLVE DISPUTES WITH ANY SONY ENTITY THROUGH ARBITRATION.
So write a quick note and keep a copy.