[OS:N:] Linux on low-end hardware?

[Robert Citek <rwcitek alum calberkeley org>]

What linux distro and setup do people here recommend for low-end  
hardware?

I'm helping out a local non-profit group "refurbish" machines that  
they get as donations.  This group then uses the machines to teach  
young kids about computing and sells the machines to raise a bit of  
cash.  Most of these machines are low-end x86 machines, e.g. <400  
MHZ, <128 MB RAM, <6 GB HDD, usually a WinModem.  Currently, their  
standard operating procedure is to triage the machine (if the machine  
is not working as a whole, remove parts and assemble a working  
machine from parts), wipe the drive, install Windows 98 and some  
application software, and configure the modem for dial-up.  Because  
of licensing restrictions on Windows98, they'd like to move to  
Linux.  The question is, what distro given the older hardware?

To date I've tried the following: FeatherLinux, DamnSmallLinux,  
VectorLinux, Knoppix (using PDI, no install), Ubuntu (server install  
followed by install of xfce4), CentOS (base install followed by  
install of xfce4).  Each distro has its pluses and minuses but  
nothing stood out at the clear choice so far.  VectorLinux using xfce4 
+ROX has come the closest to ideal.

The requirements for a distro, in addition to being able to run on  
older hardware, are:

1) look/feel similar enough to MS Windows so learning curve is not  
too steep.  E.g. start-menu, manipulating windows, configuring  
system.  xfce4 with some tweaks seems to work fairly well, but I'm  
curious to know of other's experiences.

2) simple to install application software.  Installing synaptic on  
most debian-based systems addresses this.

3) simple to clone or script an install.  I'm most familiar with  
kickstart, but perhaps there are other solutions.

4) provide an obvious upgrade path.  Ubuntu looks nicest for this: on  
low-end hardware use xfce and on more powerful hardware use KDE/Gnome.

Of course, the hardest requirement is that it has to be "palatable"  
to the other volunteers who are doing the work.  In my experience, if  
the software is too different (steep learning curve) or gives them  
too much headache (too inconsistent, buggy), they walk away.  And no  
non-profit wants to lose volunteers.

If anyone wants to share experiences or recommendations, I'd love to  
hear them.  Or if people know of blogs that already discuss some or  
all of what I'm looking for, please do post links.

Regards,
- Robert
http://www.cwelug.org/downloads
Help others get OpenSource software.  Distribute FLOSS
for Windows, Linux, *BSD, and MacOS X with BitTorrent