  We consider the universal Grigorchuk 2-group, i.e., the group such that every
Grigorchuk 2-group is a quotient. We show that this group has a nice universal
representation in the group of all functions f:{0,1,2}^N --> Aut(T_2), where
T_2 is a group of automorphism of the binary tree. Finally, we prove that this
universal Grigorchuk 2-group is amenable. The proof is an application of the
``Munchhausen trick'' developed by V. Kaimanovich.
