They're Sugar Gliders. They're tiny marsupials native to Australia, where it is inexplicably illegal to keep them as pets. They're extremely social creatures that live in colonies, and actually tend to die of depression without social interaction. They're about the size of a chipmunk, and have flaps of skin on their sides that allow them to glide like a flying squirrel.
They're growing in popularity as pets in America. While you're unlikely to ever see them in a pet store (I have once), there are likely to be multiple breeders in your area. They can run anywhere from $150 to $400 per glider, depending on the reputation of the breeder and any special genetics. Their average lifespan in captivity is about 7x what it is in the wild.
While there are lots of things you need to learn about handling them, their needs as pets are rather minor. They just need either tons of interaction with their owners or at least one other glider to socialize with, a largish enclosure, and a proper diet. I feed mine mixed fruits and vegetables, plus a high protein concoction of water, eggs, honey, bee pollen, and Wombaroo powder that lasts a couple months per batch. Mealworms are their favorite thing in the world.
Supposedly they can be trained to some extent, including learning their own names, and some have tails prehensile enough that they can pick up objects with them. They're very playful. If you carry them around a lot, usually in a pouch around your neck, eventually they will literally think of you as their home (and treat you as part of their colony at the same time). At this point, you can go anywhere with them and let them run around freely, and they'll always come back to you. They make one of the most interesting noises in nature
, whenever they're feeling upset or threatened. It's called "crabbing", and if you ever get any, you'll hear it constantly until they get used to you. Mine haven't crabbed in years.Glider Central
has pretty much all the information on Sugar Gliders you could ever possibly want to know.