Sound Greek? Well, the OBA Reference Application Pack for Supply Chain Management is a reference implementation put together by Microsoft to illustrate how we can build Microsoft Office System 2007 based composite solutions. Microsoft calls these composite solutions Office Business Applications (OBAs) and describes an OBA as being "designed to support cross-functional processes and allow information workers to collaborate" across organizational boundaries.
ArcStream is a relatively new initiative from the East Region Microsoft Developer & Platform Evangelism Team which strives to provide "a constant flow of technical information as well as networking opportunities for enterprise, application, systems and aspiring architects living and working on the east coast". A few of the key folks involved with ArcStream include Chad Brooks, Bob Familiar, Chris Bowen and Scott Jamison.
Finally, Skyscapr.net is maintained by the Architecture Strategy Team at Microsoft with the primary goal of "promoting a community-wide discussion about system architecture". The site provides access to videos, training, glossaries, ARCasts, and blogs that will help you learn more about technology architecture.
Good stuff! Now if I can just get all the way through Beyond Bullet Points. So much to read, so little time!