Forbidden You don't have permission to access /~username/ on this server.
Have you received an error like the one above, then I may have the solution for you. There are a number of posts on the web around permissions, and Apache configuration files, etc. I found that the solution was really simple, yet not obvious.
It has to do with File Sharing, you need to add the Sites directory to the list of directories which are shared, even if sharing is not turned on. See the example below.
Once you add the Sites directory to the list and turn on Web Sharing, you should be able to see the local sites for users on the local system.