One of the key things that David Allen's model has for items that you really don't need to do right away is to put it on a "Some Day Maybe List."
I wasn't so sure about this list, but after I did a big collection it was evident that I had these types of items on my To Do List (waiting for next action assignment). It was refreshing to move them off that "critical" list to something I could review periodically.
It also had another benefit. It use to bother me a great deal when something would pop up as crisis item #1 (do right now) that I had thought was something I should do in the future but hadn't really categorized it.
Over the last week or so, several of these items that had been categorized as Some Day Maybe became Priority #1. But instead of getting worked up over it, I just calmly dragged the item from one folder in Outlook to another, and added some next actions, and then started working on them.
Very neat ... having things captured and then categorized was a big stress reducer.