I have a paper based system that has been working very well for me for the last 6 months, so I thought I would share.
I use 3x5 index cards. On the plain side of the card, I write the name of the project. ("Plan class party"). On the back, I list next actions. I always list at least one, more if I have the actions in my head. For example, I might list "1. Call: Mary for class list." My cards are divided by context, so I would just drop this card behind the "calls" index divider. When I'm done with the call, I list the another next action if I don't already have one. For example, if the next action is "errand: buy juice boxes.", I would just drop this in the errand section. This way, the next action is both connected to its project and sorted by context. I also have a section for projects that don't have a next action ("needs next action"). For example, if I obtain the class list and am not immediately sure what I need to do next, I would drop the card in this section and deal with it later.
In addition, cards are color coded-- white is for child related projects, yellow is for work/business, etc. I can glance at my cards and get some sense of where I am spending my time. Also, I put a small post it flag on projects that are truly time sensitive or urgent. I limit the number of flags so I can't panic and start marking everything as urgent.
I carry all of this around in a make-up case, since file boxes are bulky and tend to open easily. The make-up case looks pretty good, is soft, and has a durable zipper. I think an alternative for a man might be a camera case. I also have a section with a calendar (printed from the DIY planner) and addresses. I filter out address cards and keep the ones I use very rarely in a index card box along with extra cards, etc. The case has enough room for a pen and small calculator. It's an odd looking planner, but it works for me. Pulling out the cards and arranging by color gives me the big picture. I have a very short outline of the major areas of my life--each week I compare my active projects to this list and try to address areas I've been ignoring.
Hope this helps! I shared this with a friend who found it useful, so maybe others will, also. I'd love to hear comments and suggestions.