There are a lot of little tools out there which can allegedly help you get more organised, better with time management, etc, etc. Personally I find most of the tools are more awkward to use and so consume time that is better spent on actually do the stuff that needs doing.
However, I did find TaskCoach which is a simple enough .exe file that I can around on USB stick, any task that needs doing I stick into there. It's possible to organise by category and to set deadlines on. It's short of a few features I would like, for example, no software seems to get the idea of chained-tasks, that is where one task has to be completed before another starts so as soon as you flag the first task as complete the second appears.
TaskCoach does have quite a powerful category system for organising items into different groupings and I'm using this to organise work tasks by week number. This is a very useful way of seeing what I've got on for the week and what can be deferred to a later week.
All in all it's a lovely little tool. Now, all I need is a checklist tool.....