Tinderbox has a feature that watches a folder in the Finder, Apple Notes, DEVONthink, and even Tot. It doesn't sync both ways, but it will import new notes from within those watched places and make new notes in a Tinderbox outline. This makes it easy to add notes to my Tinderbox file from a phone or iPad. It wouldn't be too much trouble to just copy and paste, but watched folders make it even easier.