The odd prop always adds flavour to a game, and there's nothing like having actual 'money' to pass around...
These are nicely-done 'money cards' suitable for any science-fiction game, presented in both colour and in black and white depending on your printing facilities and desires. The instructions for printing, cutting and folding are clear: it's good that these are designed to be double-sided. For best effects use a reasonably stiff card (or stick paper print-outs to card), but given as it's a PDF, if they get tatty you can always print some more.
The design is clear and straightforward, with a slightly SF feel (yet not so futuristic that you couldn't use them in a near-future game). There's some convincing legalese on the back, which looks good. I just hope the 'serial number' refers to the 'silver standard' on which the currency is based and does not relate to individual cards, as it is the same on each one. (Of course, if you are a particularly mean GM, you could see if your players notice this and if they don't haul them up on forgery charges!)
So if you run a tabletop or LARP SF game, and feel the need for some 'money' this is ideal... and doesn't cost too much either.