As Harry mentioned, about a month ago our group was fortunate to attend a presentation by David Allen, the author and creator of "Getting Things Done". I was a little skeptical as I consider myself not too bad in the "getting things done" area - and I had previously tried David's GTD Outlook add-in with mixed results.
I'll be honest - After the presentation, I was a convert. David has an exercise where he asks the attendees to dump all of the stuff in their heads to paper during the presentation. I was amazed at just how much stuff I was carrying around in (what he calls) "Physic RAM" and was determined to build a better system.
I've been using the GTD techniques (including the Outlook add-in) for about a month now and it's been very useful. I now have a complete inventory of tasks that I need to complete together with a system for making sure I can accurately capture new ideas as they enter my head (and preferably before they leave!). There is of course still room for improvement, and it will probably be another few months before this becomes a truly trusted and mastered system.
For those who are struggling with "not enough time" and "not sure what to do when I do have a spare minute" I thoroughly recommend taking a look at David's material.