I've finally decided to implement a unified GTD system. Before, I would keep some lists in text files, blog about some goals, use a checklist, etc. Backpack was highly recommended by many GTDers. I tried it and am very happy with it. Backpack is basically a web-based personal management system. You keep a collection of webpages. The webpages can be filled with lists, dated notes, links, images, and files. It's a little bit like a blog but private and more specific to planning.
So far I have four pages. 1) Home page - contains next-actions, 2) @projects - mix of project ideas and next-actions for them, 3) @waiting-for - nothing in here yet, 4) @someday - stuff I'd like to do someday when I have time, 5) Weekly review - log of what I've accomplished this week, what I need to work on based on this week's performance, and plans for next week.