from:
http://www.google.com/sms/
Send the message to the US shortcode 46645 (GOOGL on most phones)...
they've got their ass covered:
Domain Name: 46645.com
Registrant: Google Inc.
Created on..............: 2004-Sep-13.
Record last updated on..: 2004-Sep-13 11:15:43.
//
Domain Name: 466453.com
Registrant: Google Inc.
Created on..............: 2000-Jan-07
Record last updated on..: 2003-Dec-30
//
either they've been planning it for a long time or someone beat them to it and was paid very well Dec 2003.