Best Groupsite Design Practices - Are you tricking out your groupsite?

I'm interested in learning how different groupsite managers are using design principles, tools and techniques to customize their sites to optimize both form and function. If you have done some creative stuff with your groupsite, add it to this list so we can all learn how to build better sites. Here are some custom sites I know of that are pretty cool:

• https://oracleerp.groupsite.com/main/summary


• http://motorcityconnect.groupsite.com/main/summary


• http://terracecommunities.groupsite.com/main/summary


• http://community.livingwellalah.com/main/summary