I got my old crappy laptop back. I'm in the process of configuring Debian 6.0 to run on it.
With Fluxbox! Yes, we're on our merry way. I've been using Firefox (with working wi-fi, mind you!) for a couple of hours and not once did the RAM usage break 256 MB.
I'll post a tutorial and a couple of vague notes on how I did it later, because we all know that nothing attracts the ladies more. (And also because I'm bound to forget how I did it.)