A new tool I really like: dGSD
So, here's the link:
dGSD is a one page HTML file that stores everything right inside that one page. It does task tracking and supports all sorts of nice PM features.
One of the features I really like about it is linking tasks. You can link a task as a dependency of another task. When you complete you next action in a project the link task automatically becomes the new Next Action.
It's based on mGSD, another all-in-one web page solution.
The only problem I have with it is that it's not very multi-device friendly. It's one file you need to have available. I haven't tried it on my Nexus 10 yet, but on my desktop, I think it's quite slick.