The Oreo mystery flavor contest is open until Nov. 30. You can win a grand prize of $50,000, or one of five first prizes of $10,000 each. You're limited to one entry per person a day.
You can also earn bonus entries by uploading a receipt showing you bought the Mystery Oreos, which grants you one sweepstakes entry. You can also upload a picture of yourself with the package of Oreos or mail in an entry.