This excerpt taken from the DDRX DEF 14A filed Nov 16, 2006.
Q: Can I change my vote after I have mailed my signed proxy?
A: Yes, you can change your vote at any time before proxies are voted at the meeting. You can change your vote by giving our Corporate Secretary written notice of revocation; giving our Corporate Secretary a properly executed proxy of a later date; or attending the annual meeting and voting in person, provided that, if your shares are held of record by a broker, bank or other nominee, you must obtain from the record holder a proxy issued in your name. Written notices of revocation and other communications with respect to the revocation of proxies should be addressed to Diedrich Coffee, Inc., 28 Executive Park, Suite 200, Irvine, CA 92614, Attention: Corporate Secretary. See Information Regarding Voting at the Annual Meeting Proxies.