I was not really serious about that IE Mac thing (but in my experience, it is 10 times worse tham it's windows counterpart).
Anyway, I think I found what you want: http://browsershots.org/
It has MSIE6.0 but no other version
However, I made a test, and the queue is of about 1 hour :(
It is beta so unless it is one of those infinite beta services it may get better soon.