So everything I do is there, right?!
Well, no. (Yes, hardcore GTD people can laugh at me now.)
I also do things that I get from:
- my email
- meetings and casual discussions
- my IM
- habit (blogging is an example of this - I never write it down but I know I need to write content for it)
This is pretty much identical to what happens to teams during sprints. There is a great list of things that they intend to do (just like my OmniFocus items). And then there's everything else. Some of it even comes from the same places - meetings (with customers or management), email, even IM (ever had a support rep IM you with an in-progress customer issue? I have.).
Just like life, sprints never really fit on a single list. Don't forget to give yourself a little breathing room for all the stuff that's not on the list.