A flipflop circuit is nice but will be plagued by contact bounce.
True, but easily fixed.
If it does indeed have to be directional, a flip flop or some other electronic logic would probably be required.
That was my take, but macegr's cam idea is good if you have the where-with-all to make the cams (ie an axacto knife and some balsa wood :)).
Despite my being into electronics I'm all in favour of a non-electronics approach.
Rob