Kayaksailor is a product that is adaptable to most kayaks (sit in and sit on top) that makes real sailing possible. The rig includes the sail, all rigging, lee boards, and the options to add a genoa. Unlike most kayak sails this rig allows sailing in all points of wind (run, reach and beat) and performs much the same as a "Sunfish" style sailboat. The rig is not inexpensive, but the quality is high and the performance is excellent.
The video on the website kayaksailor.com says it all!