This excerpt taken from the OMEX DEF 14A filed Apr 13, 2009.
You may revoke or change a previously delivered proxy at any time before the annual meeting by delivering another proxy with a later date, by voting again via the Internet or by telephone, or by delivering written notice of revocation of your proxy to Odysseys Secretary at our principal executive offices before the beginning of the annual meeting. You may also revoke your proxy by attending the annual meeting and voting in person, although attendance at the annual meeting will not, in and of itself, revoke a valid proxy that was previously delivered. If you hold shares through a bank or brokerage firm, you must contact that bank or brokerage firm to revoke any prior voting instructions. You may also vote in person at the annual meeting if you obtain a legal proxy as described above.
Regardless of how your shares are held and whether or not you plan to attend the annual meeting, we encourage you to vote by proxy to ensure that your vote is counted. Please note that you may still attend the annual meeting and vote in person even if you have already voted by proxy.