mod_become
Has anyone tried this apache module? If it really works and has no known bugs, then this could be a VERY USEFULL module for webhost owners.
Here's a little description:
This module enables the web server to take on the access rights of a user & group, so that ~users can make available files to the web without having to make them readable by the world on the local file system. This can be useful for sites with a large number of users who want to apply file access controls among themselves. This module can also be applied to virtual hosts, directories, and locations.
http://www.snert.com/Software/mod_become/index.shtml
