I’ve implemented Getting Things Done across all my daily tech using inexpensive (or free!) solutions. It’s crosses the Mac – PC boundary (I’m sure Linux could be accommodated too) and is simple, elegant and efficient.
Scot Hanselman (and others) have a download link to the first chapter (more of a section at 1850 pages long!) totally free and totally cool. Get the NerdDinner.com walkthrough here.
You should be saving your work on a regular basis in case of crashes, but for those who forget to cmd+s like clockwork EverSave seems like a great idea.