Mechanical Engineering - Blog with many mechanical engineering articles. - http://www.mechanicalengineering.cc
Eng-Tips - Mechanical Engineers technical support forums and mutual help system for engineering professionals. Selling and recruiting forbidden. - http://www.eng-tips.com/threadminder.cfm?pid=404
MechanicalEngineer - Job listings for mechanical engineers and related jobs. Also a forum for open discussions, and a list of recommended books on the field. - http://www.mechanicalengineer.com/
ICrank - Mechanical Engineering portal site. Includes vendor and newsgroup directories, reference data, a product development forum, technical information and links to mechanical engineering resources. - http://www.icrank.com