I love SharePoint, it's easy to customize, the lists are flexible, it integrates directly into office (especially the calendars into Outlook) but I had no idea is was this community friendly.  Take a look at the "Community Kit for SharePoint" on the http://www.codeplex.com site.  It's a site template you add to SharePoint to give you community functionality on top of the SharePoint infrastructure.  Super Cool!

http://www.codeplex.com/CKS

 Scott