Integration Discussion Off to a Flying Start

This afternoon's session on integrating nonprofit software tools started off this continuing theme with some real life stories of the types of integration organizations are doing ( read the notes on the event wiki It was a really useful and eye opening session for me - I didn't realize how many different models there are for programmatic integration. The examples covered using Salesforce's API to add and edit records based on Plone transactions, integrating using a middleware layer that could map various external tools so that they could all be accessed in the same way, integrating using a complex OpenID model, and an intriguing model that involved a "deliverance" layer that was in charge of taking the information from a number of systems, including a CMS, and pulling it together into a common web interface. And no doubt there's a lot more models that just didn't happen to come up. Anyone up to try to create an overview of some of the most common integration technical architectures?