From Steve Jackson Games:
Gold is awesome. How do you make gold more awesome?
Well, we've done it. Here's a gold piece you can spend over and over again.
Each player may use one, and only one, Munchkin Quest Gold Piece in a game of Munchkin Quest. It replaces one of your 100-gold pieces at the start of a game. It is considered a Magic Shiny. Place the gold piece in front of you with the "100" side up. Any time you spend gold, you may flip the gold piece over to the Munchkin side and count it as 100. If the Munchkin side is up at the beginning of your turn, flip the gold piece back to the 100 side. If any rule would make you lose the gold piece, it remains yours, but you cannot use it for the rest of the game.
How awesome is that?