Last week I posted up a new Drupal module that attempts to improve the usability of the Organic Groups module when it's used with multiple group types and large numbers of groups. The module modifies the node edit form's audience selector, provided by the Organic Groups module, such that the groups are selectable by content type. This is useful on sites with a very large number of groups and many different group types. For example, a site like the one this was written for, with Districts, Schools and Interest Groups (all of which are content types defined as organic groups) will have have a node edit form with an individual selector for each group type.
Check it out, if you're an Organic Groups user, and let me know what you think.