How to create a views listing of all groups including a join link in OG 7.2x The 7.2x version of OG leverages the Entity Reference module to create the relationship between the group node and entity. There about 8 possible OG Entity Relationships to choose from in views that upon review seem pretty ambiguous. I just need to figure out which one(s) are required to create a join link when listing all of the groups on the site.
Add a field to your view of the type Content: Group - set the formatter to OG subscribe link - screenshots in this thread on drupal.org:

http://drupal.org/node/1816096