But this is only one half of the story.
Check the magic function
public function __call($method, $args)
Nearly every class is inherited from there.
Here you can find an array called _data.
The magic function will be called by php whenever a method call cannot be resolved by the interpreter itself. Varien uses this to check if a key with similar name exists in the _data array and returns the corresponding value.
e.g. When calling a method object->getSomeValue() on any object, php cannot find that method and will call the function __call("getSomeMethod", null)
Varien recognizes that this is a get… method, translates the rest to “some_value” and checks the array _data for this key. If found it returns the corresponding value and if not it returns null.
While this eventuelly makes sense for user-defined attributes (however a simple getAttribute($name) would do the same job), it is truly horrible to use it so heavily. From my point of view, Moshe and his team should consider at least to minimize the use of the magic functions in the next few releases.
So if you really want to know which methods are possible, consider using print_r(object->getData()); or similar constructs.
Hope this helped a little.