Andrew Hayes has recently developed an all-purpose program (January, 2012), Process, which handles all forms of mediation and moderation as well as various combinations. Documentation, SPSS programs, SAS programs, sample output and more can be found at:
http://www.afhayes.com/spss-sas-and-mplus-macros-and-code.htmlI hope this is helpful,
Stephen Salbod, Pace University, NYC