At the first OMP, back in June 1998, everyone who registered at the door had to submit one marble as the entrance fee. Later that night the marbles were raffled off. The winner of the marbles decided to donate the marbles back at the OMP the following year, thus starting an OMP tradition. Every year the marbles are raffled off, get to spend one year with the winner, then are raffled again the following year.

Marble winners

• August 2003, Pittsburgh: William and Dreamer from State College PA
• August 2002, Baltimore: Vryce and Stalin from Randolph MA
• June 2001, Las Vegas: Stranger from Cleveland OH
• July 2000, Cincinnati: Shadowhawke and Anya from Chicago IL
• July 1999, Chicago: Taffy from Boulder CO
• June 1998, Washington DC: Frogurt from Quincy MA