I suppose I should really update the status of various things I've mentioned in the past.
xsm: I gave up and just added the appropriate magic to my xinitrc to start my common apps. I tried fluxbox again for a while, but although it could cope with one of each app it didn't seem to do too well with half a dozen xterms. Maybe with a little effort it could, but xinitrc does the trick well enough.
Netgear DG834G: I wrote up a page of info about this, just to have something static. Unfortunately it seems that the Marvell 88E6060 switch chip used only supports port based vlans, which I think means you can split the switch up so that you can have completely separate ports, but doesn't allow the creation of a wan port on the device. This is a shame, as it means I can't use it to handle my setup unaided (I need wan, lan, wireless + adsl ports).
X11 programming: I ended
up using SDL, which gave me a framebuffer to play with. I suspect I could
easily convert the code to run on
/dev/fb0 directly, which is nice, though
I should look at how to do the same with X again at some point.