When we play with more than two people on Monopoly Deal, we have devised a rule:
Your only exposed card in your bank pile is the top card. All other cards may remain hidden, as to add an element of strategy during action card play.
This does introduce a possible element of cheating, as a player who wishes to deposit two or more bank cards in a single play would have little trouble concealing their effort by stacking their cards directly on top of each other, and then burying those cards in a nice, straight pile that no other player can gauge value on. Of course, we're all friends at the Monopoly Deal table, so cheating would just be a silly waste. In order to pay a fine, a player may pick up their entire bank, and select without revealing its contents to the others.
As you can imagine, this creates a new element of strategy to the game. At one point, I was about to win, and was charged money by everyone on the table. The person before me had no idea I was holding the $10M bill, and I survived the ordeal and won out. Had they known sooner, they may have pinched my bank previously, and I would have had a harder time winning.
Does anyone have any suggestions? Official responses? Does anyone else do this besides me?