[whpalmer4]

Yeah, I understood what you were saying, and just wanted to expand a bit on what you could do right now. What's there now is useful, if restrictive.

I think the document interchange stuff in iOS right now (on the drawing board for OmniFocus, but not shipping yet in a general form) in conjunction with something like Dropbox might allow what you want without having to make the big "container app" you mention. I don't know how interested Omni is in hitching their wagon to someone else's horse, however. I'm also not sure how easy Apple has made it to get a reference to some other app's data; clearly there is a path to say "here's a file, please open it" but I don't know if there's a means to say "give me a handle to this file I'm giving you that I can give back to you in the future and have you open it"...