The fundamental group of the Hawaiian Earring is not free. However it behaves like free and it can be used to develop a theory of generalized presentations of groups. We give clear generalized presentatons of any symmetric group and of the automorphism group of the free group of infinite countable rang. This is a joint work with W. Singhof.
Links:
[1] http://www.mpim-bonn.mpg.de/taxonomy/term/39
[2] http://www.mpim-bonn.mpg.de/node/3444
[3] http://www.mpim-bonn.mpg.de/node/158