Multi-site / Multi-account sites

We might consider ways to make the following easier in future versions:

1) Host multiple sites from the same installation. Maybe an extended version of Raymond’s plugin installed by default or a an extended static content publisher ala Bricolage that can build to an FTP address, including pushing CSS and Images.

2) Have master accounts with multiple logins linked to that account. This would be great for custom web services/hosted applications (think 37Signals’ Basecamp). Perhaps we add an owner ID column to each relevant data resource in the system (widgets/content fields/templates/etc)? Perhaps an ID of 0 would mean that they’re publicly visible to all accounts while any other ID would go to "accounts".

Thoughts?

The Subsites plugin is just a demo of how Subsites will work inside the core. So no need to include it as a plugin.

And Jason pointed out via IM that sub-accounts for users is simply an additional column in the groups table (parent).