undo for movement

[Joe Corneli]

Is there a way to "undo" movement?  Say I press M-<, M-e.  The first
time I ran the command I'm thinking of, it would have the same effect
as M-a.  The next time I ran it, it would have the same effect as M->.
I would also like the command to interact nicely with search; if I run
C-r nex C-e, for instance, the cursor should get taken back to its original
location again after two "undos".
                                 ^