The first part of the solution is that, as was hinted at in the first chapter, Gitolite allows you to group repositories in subdirectories, just like you can do with files in a filesystem. For example, you could put all the open source projects you're managing under a subdirectory called foss, like the following:

repo foss/apache
    ...access rules for the apache repo...
repo foss/linux
    ...access rules for the linux repo...
...etc...

We can make use of this in solving our current problem. Let's say we had users Alice and Bob, and we wanted to let them create and manage repositories. We could come up with a way by which Alice's repositories would be in a subdirectory called, say dev/alice, and Bob's repositories would, similarly, be within dev/bob.