[mytreeoutside]

With all this talk of webDAV and Dropbox, I thought I'd mention:
You all considered DropDAV, right?

To whpalmer, that might make your graffle workflow a little smoother. And, if omni supports WebDAV and not Dropbox, there's your best of both worlds.
Unfortunately, and for reasons beyond my understanding, I get errors when trying to use it with OmniFocus. I imagine it has something to with the OF file structure.