Reuven, check out
GrandEx. It was built by aD, and makes good use of subsites.
Subsites might turn out to be the killer application for openACS. Being able to provide a complete web presence for a parent organisation while allowing each subsidiary to customise its own look and feel is not as unique a requirement as one might think.
As PhilG might put it, it becomes a lot easier to build purposeful communities around particular subsidiary/product/brand/department/region .....
With subsites, portals, groups and host-node-mapping (dotLRN anyone?), one can build some really powerful websites!
