Haven't done it on a quilt yet, but just did a placemat (tried some straight line quilting last night) and used a take off on this pattern
http://www.thequiltcompany.com/SUPERSIMPLEPLACEMATS.pdf
Very similar to this posting on the QB
http://www.quiltingboard.com/t-60160-1.htm. Worked like a charm. You could make any size binding you want using this method.