I like rememberthemilk too. Trello seems to work well for visual people (that's me). As Merlin Mann says, the second your tools start being fun, you've gone t

I like rememberthemilk too. Trello seems to work well for visual people (that's me). As Merlin Mann says, the second your tools start being fun, you've gone too far. The key thing is the process: making a contract with yourself to do the work and then defining small physical tasks that you'll actually do.