Design Pattern in PHP: Borg pattern

I thought about sharing some design patterns (expressed in PHP) I have documented. The first one is the borg. This design pattern serves as a good alternative option to the well-known singleton pattern.

The advantages of the borg are:

1. no need in client classes for special creation / access methods
2. easily sub-classed
3. more easily testable
   

Project
The project is located at GoogleCode.