my variation on waiting for
I still have an @waiting for list, but I too find it somewhat passive. What I've begun experimenting with is using the ~ symbol (i.e, the tilde for those of you who speak spanish) in front of items I am now waiting for. For example, "send Jim my April plans and itinerary" was an action in @emails. But then once I did it but needed to pay attention to the fact that I was waiting for a reply from Jim in order to finalize my plans, I put the ~ at the front of the description of that task. So as I scan my lists of emails, the ones that begin with ~ are in someone else's court at the moment. I can still read them and decide whether I should nudge them a bit, but it's not as much a required NA like the rest of the ones on my list. Since I use Outlook, the other option would be to quickly ALT-G to change the item from the @emails to @waiting category. But if I am going to want to follow up it will likely be in that same context (i.e, emails) then why not leave it in that list, modified by the ~ ?
Not sure if this is inefficient or GTD heresy in others' opinion, but it seems to help.