The California Supreme Court has announced on the California Courts website that its Los Angeles Clerk's Office will close at the start of the new year.  The Notice states:

Notice

EFFECTIVE JANUARY 1, 2010, the Los Angeles Clerk's Office of the Supreme Court of California will be closed. The Supreme Court will no longer accept filings at Court of Appeal locations. All petitions for review, writs, and legal briefs must be filed at:

Supreme Court of California
Office of the Clerk, First Floor
350 McAllister Street
San Francisco, CA 94102

The Supreme Court will continue its practice of conducting oral argument in Los Angeles, typically in the months of April, June, October, and December.

Update on Tuesday, December 22, 2009 at 5:19PM by The Complex Litigator

The UCL Practitioner has additional helpful comments about alternative methods for filing briefs under the Rules of Court.