Miro Svrtan has a new post today proposing something that could be added to help handle bad method calls in PHP apps - using the BadMethodCallException (pre-existing) instead of throwing fatal errors.

Using getter method that is not implemented will get you fatal error saying how undefined method is called and request will stop. [...] On the other hand if you would use public property all you would get is a notice saying how this property does not exist and rest of request would be completed. [...] I know that this is due to dynamic typing behavior of PHP and no I am not suggesting raising a notice if undefined method gets called but since 5.1.0 there is a BadMethodCallException class which would be perfect for this situation.

There's been other people that have proposed the same idea as a bug, but nothing formal has been submitted as an RFC to make the change. Miro is looking for feedback to find if others would be interested in this feature and want to make the proposal (leave comments here).