There are a couple of projects in the works that take an interesting approach to this. Because the image/VM is always running you can essentially "turn on" a c

There are a couple of projects in the works that take an interesting approach to this. Because the image/VM is always running you can essentially "turn on" a checker that will note which classes of objects have been sent as message arguments to some method. After a while you have more or less a list of "types" that a given method understands because of what the system has experienced. These can then be used for type hints in the IDE. This approach is doubly interesting if you work with tests, because simply running a test suite you think is fairly comprehensive will result in a pretty good set of types.