These marble picture fridge magnets thingys make great stocking suffers. Useful too, to stick on the fridge or on any metal surface, such as a file cabinet. They keep papers from flying everywhere or just be used to decorate your cube. The marbles you need for this project are very easy to find. Try home decoration shops (people put them in jars to decorate) or gaming stores (they are used as tokens in many board games). As for the magnets, you can use any small magnet, really, but the best would be to use rare earth neodymium magnets (not rare heart as Ive seen in a store). You can easily order them online if you don’t have any.

DIY Marble Magnets [link]