Nisus Writer has 'link back'
in essence if you have a graphic in your file, you can double click on it and it links you back to the program that created it to change it.
I am thinking some for of this --- especially with OmniOutlner would be cool... I can import OO files --- but they are a list. I can change that list, but that would make it so my OO file is out of date....
any thoughts.......?
