I saw these coasters at a quilt shop last week and asked about the pattern. They were nice enough to print off a copy of the pattern. Below is the link. They were really cute - the bottom of the wine glass actually fits inside the coaster so if you pick up the glass, the coaster goes with it. And you could make them all different so everyone can easily keep track of their glass.
http://www.creativegridsusa.com/_med...oastersUSA.pdf