For some time now Ditte has been running a form of After Action Review in Oracle that she calls Proactive Reviews. Its a similar process to AARs but with a few key improvements that make it a very powerful business tool.
Oracle, for example, runs a high-level Proactive Review after every merger and are one of the few organisations I know of that have taken AARs seriously and are applying them in a systematic way in the business.
If you speak Danish you can hear what Ditte has to say about them here:
Also take a look at Ditte's website (this is in English). The book is currently only available in Danish but an English version will be published in September this year.
I'll be talking more about the process then as I think this is one of the more exciting things to happen in KM for a while.