Abstract: A clip system for use with tarps and other flexible sheet material. The system includes first and second parts that are rotatably mounted so as to be free to twist independently of one another, in response to wind or other forces. The first part may be a clip body having jaws for gripping a tarp or other flexible sheet material, and the second part may be an attachment fitting for engaging an article separate from the tarp. There may be a series of different attachment fittings that are interchangeably mountable to the clip body, such as a hook, a screw-on fitting for attachment to a bottle that forms a weight, or a fitting for attachment of a strap or shock cord, for example. The two pieces may be joined by a male coupler and a female receptacle that receives the coupler in locking engagement. The male coupler may have a plurality of resiliently flexible legs with beveled end surfaces that flex inwardly to pass through the opening of the female receptacle.