Hasbro has released a new edition of Monopoly called Ultimate Banking, that should help keep familial infighting to a minimum. Instead of paper money, which can easily be laundered or stolen when you aren't looking, this new edition uses debit cards. It also does away with the easily-corrupted Banker position, replacing the human with an electronic card reader (aka an ATM).
Both the players' debit cards and the property cards themselves will be machine readable. So, when purchasing property, players will first scan the property's bar code and then their own cash card. If they have enough money for the transaction, the funds will automatically be deducted from their account. Funds can also be transferred between players, if necessary. Removing the human influence should certainly help keep the financial shenanigans to a minimum -- just hold on to those debit cards. Monopoly Ultimate Banking will hit store shelves later this summer for $25.