xiadyn posted about Hiveminder, and I was curious, so I signed up. It is definitely the closest to my personal ideal to-do list manager, out of the available contenders. It's still not perfect, but the "Braindump" feature is approximately what I wanted such an application for, and what gubb and some of the GTD-recommended ones don't do. I'll probably use this for now, in the interests of not being a hypocrite, but continue hacking on Petitpoint to make it do my BIDDING.
(it also provides a sort of excuse to legitimately play with Ajax and to put together a personal site around it. That, and my awesome!shiny scanner from miss
phinnia, which is greatly encouraging my drawing habit.)