I've started playing about with TaskPaper 3 as an alternative ToDo solution. I'll never leave OmniFocus 2 for my detailed project planning and 50,000 ft view tasks, however there are times when a plain text solution is what I'm really after. I'm migrating a lot of my notes and research to plain text files in Dropbox, with indexed links to DEVONthink Pro Office and TaskPaper 3 fits in with this workflow well.
This link gave me some nice tips and insights into how to use it effectively. I'm far from being a pro but I'd like to think I'll be in a position soon to produce an online beginners guide to Taskpaper here for you very soon.