Only in the US I'm afraid...
Pepsi is running a sweepstakes competition, giving away an Xbox 360 every 10 minutes until 10/31/05. Starts 8/28/05.
"To play, consumers will collect
codes found under the caps of Mountain Dew and other participating
Pepsi products, and enter codes in a personal online account at http://www.every10minutes.com.
Participants will be able to choose which 10-minute drawing to enter,
and can spread codes across different drawings or stockpile codes and
put them all toward one drawing. In addition, codes entered will
automatically earn the participants points toward obtaining collectible
merchandise and gear."