I just viewed your link on the OO approach. Very nice and educational.
I am trying to envision how this would work with my project. Not sure yet.
Although I am having some issues with the coding, the project is not as large on the back-end as people may assume. I will be storing much data, but the actual processing is simple.
One of my main concerns is security (A topic for a later time).
I will have to keep in mind your fine example of the keycard/lock. How does this relate to this project? (Rhetorical)
I believe this approach may be good when handling the registration of new Users, a process more complex than people think. Plus, I'm building my own, advanced Captcha system, so the OO approach may work there great. Also, I'm designing a security-bot; More on that in the future.