I started using a D.I.Y. Planner referred in some circles as a "hipsterPDA". The whole concept is an offshoot of David Allen's "Getting Things Done" book. I have the David Allen book but never found the time to read it all. I am starting to use this tool on the mac.
http://weblog.bignerdranch.com/?p=23Freeware with source code available. Lots of templates and I can import iCal and Contacts from the iBook. I "get things done" by using one hipsterPDA updated every week. Excellent stuff especially the project planners and Priority Matrix. I love "to do" lists because I can physically cross things off and by the end of the week if I feel that I am not "getting things done" I can review the list and pat myself on the back or figure out where things went wrong.
David