Kinkless GTD
I found the Kinkless GTD System via this post on 43 Folders and it does kick major ass. I was trying to find something similar for a long time, something that allows me to manage my tasks in an easy way and giving me a good overview about what happens next and what is waiting, keeping your head clear. If you have OmniOutliner Pro, try it out, otherwise download a trial or just buy the damn thing. :)