For hosters reading this who want to offer SharePoint based
hosting solutions to customers, please make sure to check out the excellent "Creating Shared Hosting Solutions on Windows SharePoint
Services 3.0" solution guide that Microsoft shipped this past
Monday. It provides really detailed instructions and prescriptive
guidance on how to best deploy and manage SharePoint in a shared hosting
environment, and enable thousands of customers to run on a single shared
hosting server.
Hope this helps,
Scott