The Science of Baseball
This site explores the physics of baseball with interactive activities and interviews with players. 

PE Central
This is a site for phys ed teachers, students and interested parents. Included is the latest information about developmentally appropriate physical ed programs for children and youth. It also includes lesson plans and assessment ideas.

SportsKnowHow
Premier site offering Field and Court Dimensions, History, Rules and How To Information for a variety of sports right here in one place.