I just implemented GTD this week. I'm using gentoo linux on my laptop and home desktop. I have a folder called GTD which has separate text files containing lists for projects, waiting_for, someday_maybe, a whole folder called next_actions which contains separate lists for each context, as well as a few other folders containing various lists. I like keeping them in separate files so that I can easily append items from within a terminal or the mini commander in my gnome panel. I hate to be a downer on Merlin's appending "trick", but it seems unneccesarily complicated and, well, trivial when it's faster, simpler, and fool proof to just do it with shell commands. I use unison to sync between my lappy and desktop. The desktop runs a webserver, and I could (though I haven't yet) easily put a symlink in public_html which would make my lists viewable from any web enabled device. Come to think of it, it would be pretty easy to write a php interface that would display and allow editing of the lists... but so far I'm happy with what I have.