My preferred device for top-rope solo climbing is the Petzl Mini Traxion, used with an anti-cross-loading carabiner :
Here is my basic anchor setup (note that the end of the climbing rope is weighted and that a second strand of rope is used as a back-up and a rappel line):
Matthew is a full-time professional climbing guide with more than 12 years of experience and the owner of Earthworks Climbing School. Matthew is a certified-member of the American Mountain Guides Association and the Professional Climbing Instructors Association. Matthew's other specialties include California Natural History, telemark skiing, gourmet coffee, and backyard astronomy.