PHP's object model has a number of quirks that one should be aware of: a lack of private/protected variables or methods, no multiple inheritance, no interfaces, etc. I call them quirks because while the object model isn't a match for Java, PHP isn't Java - and that's a strength, as well as a perceived weakness.

The things you can do with PHP - easy string manipulation, variable variables, variable functions, variable classes, variable method names, to name just a relevant few - are both the reasons you should be using PHP, and the things that can make the object model, "impure" as it is, wonderfully elegant to work with.

Actually using PHP's OO features is beyond the scope - and to some extent, the point - of this presentation, but if you're unfamiliar with it, you'll probably pick up most of it through examples by the time we're done.