eFunda, which stands for Engineering Fundamentals, provides a single source for mechanical engineering reference information. Managed by a group of PhDs and others with extensive experience in the working world of mechanical engineering, the site is divided into six main areas: Materials, Processes, Formulas, Design Center, Units and Constants, and Mathematics. Among the useful material at this site, the Materials section provides a convenient listing of mechanical and thermal properties for different types of steel. For another example of the material found here, the Formulas section contains quick reference and refreshers for beam equations, and formulas pertaining to fluid mechanics and heat transfer, among others. This comprehensive, searchable site is neatly organized and should be a handy source of information for mechanical engineers.