Here you'll find the profiles of the finest professionals in the Open Source eCommerce world.

There are public groups created for the different shopping carts, and also country specific groups.

Upon registration you are asked to fill out your profile. Once registered, you can maintain a blog, upload pictures and video's and become a member of the different groups, as well as create your groups (public or private).
Each group has it's own forum and sections can be added for rssfeeds, and a whole bunch of widgets.

Anyone can read forum messages, but to post you have to be part of the group.
Similarly, on the main site, anyone can view the messages, but posting requires registration.

There is loads more you can do, to find out I suggest you give this a spin, or have a look around at other sites such as http://tudiabetes.ning.com/groups

Have fun, and spread the word !
Carine