All those categories sound complicated to me -- as a person struggling with time management, I have found that the simpler the system, the more I am inclined to use it daily. Sadly, there is no one magic pill that works for everyone (just like with diets); all the systems work, but only when you use them regularly. It really all boils down to what you'll want and like to use every day, so there is no use to implementing a fancy system if you won't use it in the end because it goes against the grain of your life/mind/design taste ;o)
I have been using a system called Autofocus that is simple and fits the way my mind works ;o) It's one huge to do list, and I mix up all my to do list items there -- do laundry, email prof about paper, cousin's wedding at 2 p.m. on Saturday, finish reading paper for class, friend says I should finally watch "Strictly Ballroom", fix window handle... I have a small moleskine notebook for that list that I tuck into my moleskine journal (same as yours, Helofamess!). The Autofocus system is, in a nutshell: Whenever something pops up, add it to the list. Read the list and pick an item you want to do. When it's done, cross it off. If it's not entirely done or needs follow-up work, cross it off, and add it as a new item to the end of the list. I know you're probably wondering about the "want to do" part, and no, I'm not petting ponies and picking flowers all the time ;o) When wondering what to do next, even without having the list items assigned a priority or a category or whatever, I quickly learned to distinguish between urgent and important.
To adapt it to your need of "seeing it all at one glance", I would suggest to maybe just take a really big notebook. I'm not saying you're supposed to use Autofocus now, just saying that to do lists are possible without over-organizing them. So even though you say you need your 15 categories -- if you have a system without categories, you'll just know the matching one when looking at the task (after all, you don't do laundry for your English professor, and you don't write a math paper for your mom). :o)
Oh, and since you said you have an iPhone -- Teux Deux recently added an iPhone app. It's a simple and beautiful electronic to do list and weekly planner. I'd definitely use it if I had an iPhone and if my mind didn't remember things better when I write them down by hand ;o)
Also, there is a thread in this forum called What personal information manager do you use? where there are quite a few tips, tricks, links and suggestions for electronic and 'old-fashioned' calendars, planners and systems.
Good luck, and tell us what you come up with and what works for you! :o)
