I got a very good question today from a TAP customer last week which I hope is generally applicable.  The customer asked “What can I do with the web service interface?”  Fantastic question!  With the web service interface, you can….

1. Do everything the portal does.  (The portal uses the web service interface for all requests.)
   1. Create and delete groups.
   2. Add and remove members from groups.
   3. Create and delete users.
   4. Configure synchronization rules to provision users and groups to connected systems like AD.
   5. Configure management agents and the metaverse using ma-data and mv-data objects.
   6. Create calculated groups and read their resulting calculated membership.
   7. Create workflow definitions and configure policy to fire these workflows upon changes in the system.
   8. Search for objects with complex queries.
   9. Save searches for objects by using Sets and configure the system to take action when values in the set change.

If you are considering batch creation of groups or objects or are looking for a good integration story with another product, I invite you to consider using the web service interface.  For more information, I recommend reading my previous post on this topic.