For those of you that use an Android phone or tablet – whatever reason you may have for that – you will enjoy this AppleScript published in the OmniFocus forum. It allows a certain level of synchronisation between OmniFocus for Mac and ToDo.txt format via Dropbox.
When you mark an action item completed in todo.txt, the script will mark it as complete in omni when you run a sync with it. If you create new items in todo.txt, the script will also add these times to omni (including info about project/context, etc., if you have added them). Items without a project, are added to your inbox. Items with a project, should get added at the bottom the project's task list.
I understand that there are a number of apps on Android that support Todo.txt and integrated with Dropbox. As usual with these sort of scripts I highly recommend to make a backup of your OmniFocus database before toying around with it.