I have been using «Life Balance» for a couple of years now. But only since I read GTD recently, can I fully take advantage of this wonderful tool. Therefore, I'd like to encourage you to look at this tool (definitely not a toy), if you haven't done so.
The great advantage of «Life Balance» over Outlook is, that you can organize your task hierachically in an outline style overview. This is where I organize my projects and loosely coupled tasks.
Each project or subtask can then be assigned to a place. For each place «Life Balance» automatically provides me with a separate todo list.
So I use places such as @home, @office, @phone etc. I also use places like "meeting-abc" or "contact-abc" and also places @waiting for... and "sometime/maybe".
The great thing about this method is, that I can easily assign task to lists, because lower tasks in the hierarchy automatically get assigned the project place (e.g. @next steps). But I can as easily reassign places when a task in @next steps has to go to @phone or @waiting for... without moving the task in its project context.
«Life Balance» even helps me to prioritize my work lists by balancing my efforts in the various projects according to my own weight settings.
Of course, «Life Balance» supports mac, windows, palm and lets you synchronize the palm with the desktop editions as well as with your calender, todo-lists... and thus, indirectly with Outlook and Lotus Notes. Check it out at www.llamagraphics.com