theme gallery and multi-theme

Hi,

1. Is there a gallery of readily available themes somewhere?  Can you provide pointers to some pre-configured themes with custom look&feel, navigation, etc.  similar to

http://www.mezzoblue.com/zengarden/alldesigns/

 

2. Also, can each group select/change to a different theme - i noticed a discussion on this topic with Brett's MyTheme plugin - but no updates on same for over a year - what is the latest status ?

We are evaluating Elgg for a project and need to know what's possible/easy/difficult, etc. If you have suggestions, plz reply.

Thanks.