How Document Your PHP classes

So you've read about how Object Oriented programming can help you with your big web projects and you've started it using with PHP? If you've already written a handful of classes to implement a site and you're methodic, then you should have written some documentation about them. But If you're just messy like me you've just written some comments within the classes' source and no other documentation. Without documentation it's difficoult to remember methods' names and the way they have to be used (parameters and meaning). The typical way to solve this situation is to have source code files open and to skim through hundreds or thousands of lines.