You no longer need to undo undo undo undo undo undo undo undo undo undo undo............. Just run this script and it will open a window that shows all your undo's. Just double click on the undo that represents how far back you want to go and you're done!

*Warning* - use at your own risk. I believe this script works just as it should, but you never know what's around the next corner...

Installation:

Copy and paste the contents of this file into a custom shelf button command or into the command of a new hotkey. I personally have this mapped to Alt+z on the keyboard.

This script requires you to have a "C:\mayaundo" folder. You can change this to wherever you like. Just remember to update the TWO PLACES in this script that reference the path.