Microsoft, in partnership with community organizations Culminis, INETA and PASS offer user groups a platform to promote their groups, publicize events, and get funding for their communities: User Group Support Services.

One platform, covering Developers and IT Professionals makes finding an event worldwide very easy: http://www.ugss.codezone.com/ (Events Calendar tab)

For User Group Leads, you benefit from a Global Speakers and Sponsors Bureau, Event Management, Member Management and Meeting Content. User Group leads can register on http://www.ugss.codezone.com and quickly get benefits for their community.