It's all a goofy-ass gimmick to promote a foreign exchange company, but a group of "scientists" has developed QUIDs—Quasi Universal Intergalactic Denominations—rounded polymer chits to be used for transactions "in space."
"None of the existing payment systems we use on earth - like cash, credit or debit cards - could be used in space," said Professor George Fraser from the University of Leicester.
"Anything with sharp edges, like coins, would be a risk to astronauts while the chips and magnetic strips used in our cards on Earth would be damaged beyond repair by cosmic radiation," he added. ... "In the fullness of time we will have to adopt a universal currency if we are going to carry out serious commerce in space. It's an interesting initiative."
[Redacted] said: "It's only a matter of time before people will be walking up to our shops and asking for Quids for their two weeks in a space hotel."
Before QUIDs all the astronauts on Mir had to wash out Russian food tubes to get a hot meal. I'm sure a pocket full of QUIDs would be worth the several thousand dollars in fuel expenses.
New currency for space travellers [BBC] (Thanks, Sandra!)