My articles recently have all focused on new hardware -- the latest and greatest that is available. However, this ignores one of the strong points of Linux: that it can function on hardware that by today's standards is rather old. This is useful for schools, and for those who can't afford that brand new laptop, but can probably afford a used 486-33 laptop from EBay.
The key to getting Linux to make old hardware useful is to not expect too much of it. A 486-33 simply will not run Mandrake 7.1 with Gnome 1.2 and all the latest bells and whistles. It will, however, run a minimal version of X with a light-weight window manager. So, you need to plan accordingly. You'll also want a light-weight kernel with as few options as possible to conserve memory, and you'll want whatever distribution you use to be as small as possible -- the bare essentials.
What will this give you? Well, in the case of a laptop, you will have a machine suitable for typing, taking notes, doing spreadsheet work, checking e-mail, and even browsing the Web. If you feel you can live without a GUI, you're even better off. Once you get a network card or modem that works with Linux into the thing you will have a fully functional laptop with Internet capabilities, something which can definately come in handy if you are in need of computing on the road, but can't afford much. In the world of Windows, this would (essentially) be dead hardware, but thanks to Linux and its focus on being able to run on a wide range of hardware and without heaps of space and RAM, you've now got an mobile Internet-capable machine, capable of doing real-world work, to an extent.
What about on the desktop? I know many people who have 386 and 486 systems lying around their house -- machines they don't think are worth doing anything with -- not good enough to be given away, not quite old enough just to throw out.
Well, fear not, that machine can be made useful again. With a little work, you can get Linux installed on it and have a fine machine for someone to use for word processing or Web browsing. With a desktop, it's even easier than the case of a laptop, because you can probably get an ATAPI CD-ROM running, and you might be able to get X running at 640*480*256. You aren't going to be able to get Netscape 4.x running on it, but perhaps a Web browser like BrowseX, which is focused on being fully functional and small and fast (and, coincidentally, was featured in an article here recently), and runs well on a machine with 12 megs of RAM! Again, this is a great example of Open Source programming going back to its roots -- back to when programs didn't need a quarter-gigabyte of RAM just because the programmers knew most people would have it or could get it.
In the end, given maybe $50 worth of hardware, you can build a system for someone to use as a Web browser or a word processor, or something for a child interested in computers to toy around with without worrying about breaking it. A computer like this could even be given as a gift; it's a nice starting point for someone wanting to get into computers, or for someone who doesn't need bells and whistles. For instance, I'm planning on building a machine like this for my grandfather -- all he wants to do is be able to type up and print out newsletters he sends out to the family and to his classmates, who he still talks to, and perhaps get in email contact with our family. For things like this, a machine like this is perfect: inexpensive and effecient.