User Experience is more than a buzzword. It's a design philosophy and process that has been proven to work (think Apple, Inc., Hewlett Packard, IBM).
Join to meet others that have experience using User Experience techniques and standards. Also, gather to perform usability testing for your site or a client site. If you're familiar with User Experience you know it's all about testing and gathering data on the users for the product, and not assumptions or decisions from the client or developer. This group will cover all fields of Human Computer Interaction that includes: User Experience, Usability Testing, User Research, Visual Design, Information Architecture and Interaction Design.
Even if you have no clue what this is, and keep seeing people talk about it, join. You are the user of products that one of us in the group might need to help develop their product.