UFO's are a brand of clothing extremely popular in the "raver" community. Your average article of clothing produced by said label is a pair of nylon pants, with a profuse surplus of cloth in them. They are identifiable by the useless pieces of cloth dangling from the cargo pockets on the outsides of each leg, as well as the ability to shoplift a refrigerator in each pant leg. They come in many colors, from black and white, to soylent green and camo. They are available in malls, trendy consignment shops, as well as online. The average pair of said pants costs about $50 American, but I've seen them range anywhere from $35-$80 a pair. The same brand also makes t-shirts, skirts, and accessories. I own one pair of said pants, in an olive drab color, and they are my favorite pants. Many of the people wearing these pants defy the "raver" stereotype, and they are becoming quite trendy.

See http://www.ufojeans.com/ for a look at some of the styles available.