I've hacked on this for a couple of hours, and it's not that simple. You can do it for bare functions and maybe other specific situations, but those solutions fail for instance methods or class methods, or some other situation. [This code](http://pydoc.net/Python/remember/0.1/remember.memoize/) attempts to do it, and needs three separate decorators (for functions, methods, and properties). And I don't think it maintains introspection. I'll rework the tests to track hits and misses, but if you really want it tracked by the decorator itself, I think we should do that in a separate PR and not block this one.