> You can do this with a Hash already:

Sure (I learned that from Ruby Best Practices. great book!), but I
would like to argue that it's a bit more tidy to define a class (a
subclass of MethodHash) in one place, which I can then reuse for
anything I need to. But I don't claim to have revolutionized the world
with this. :)

>
> Granted, serialization to a file needs a few lines more.
>

The use I have of it is that some calculations I have made that took
some time to do, is easily available at any time later by just
remembering the class name I used for it. Maybe the name MethodHash is
misleading...