LinkBack

LinkBack is a way of embedding content between applications in such a way that you can always go back and edit the content with the software that created it.
For lots of information about LinkBack, and a list of applications that support it, check the web site at www.linkbackproject.org.
OmniOutliner works as a LinkBack client, which means you can embed LinkBack data from other applications in your OmniOutliner documents. OmniOutliner is not a LinkBack server, though; you can't embed OmniOutliner data in other applications' documents. For example, you can copy some graphics from OmniGraffle and paste them into an OmniOutliner document as a LinkBack attachment, but if you copy rows from OmniOutliner and paste them into OmniGraffle, they will just be normal text.
To embed data from a LinkBack application in an outline, just copy it from the other application and paste it into OmniOutliner.
To edit other LinkBack applications' content embedded in an outline: