Is there any way to dynamically add a method to a class?

[Joseph Ryan]

So, I know how to use find_method to get a method from an object;
but is there any way to dynamically add a method to a class?
Basically, I want to do something like this:
   newclass P2, "Foo"
   new P1, P2
   
   addr I0, _Foo::somemethod
   setmethod P1, "somemethod", I0
   findmethod P0, P1, "somemethod"
   invoke

So, how do I do it? :)  The only way I could figure out that might
work was to make my own pmc class that held an alias to the class
pmc itself as a property, and then treat the class itself as hash;
however that seems extremely hackish, as well as pretty slow, as it
would take an extra lookup to find the method.  Any tips would be
greatly appreciated.
- Joe