Since then my computer network has grown unchecked into a hodge-podge of quite old beige PC towers plus a couple of hubs here and there.
A while ago I decided to embark on a project to try and reduce its energy consumption because it was preposterously large as a proportion of the daytime base load of the house.
Having now been through the exercise, I'm able to calculate whether it's been worth it or not.
It just became simpler to rescue a box from Freecycle and add it to the network, than to muck about with things like dual/triple/multi-booting a single box.
Nonetheless, some things ended up being on all the time anyway - notably a media server and a mail/dns server.
Then - comparatively recently - along came a massive improvement in hardware virtualisation technology, which allows you to run many independent virtual machines ("VMs") on one physical piece of sufficiently capable hardware.
I picked VMWare as my virtualisation platform, there are others but this was simple to experiment with and has the huge benefit (to me) of doing what it said on the tin right out of the, er, box :-). Xen may be wonderful, but trying to get my head round it quickly wasn't.
Anyway, the upshot of the experiments was that I've managed to replace my physical DNS and mailserver, the media server, two Windows boxes (2000 + IE6 and XPHome + IE7) and a development webserver with VMs running on a £400 laptop from those nice people at the Linux Emporium and an IcyBox RAID network attached storage appliance.
The house's daytime base load is down by around 200W to a much more acceptable 350W - which is a 40% saving.
Plus I'll finally be able to get some space back!