My brother once showed me windows XP running on his (now mine) Zaurus SL C-1000. I tried looking around on how to do this but nothing came up. Is this possible, or was he pulling my leg?

You can use VNC to remote control a computer that is running xp. I've done this before, and it will look like you have xp running on the device. Windows XP is designed for x86 based CPUs. the zaurus' uses ARM CPUs, so it is a different architecture.

So, can it not be done? I thought you could emulate an x86 processor with an ARM, just made it slower.

It will be so slow if it worked there would not even be a point. Running dosbox on the zaurus is even slowed down a little.

Why would you want to run such a crappy OS on a very small/old/slower device anyway?

Its possible. Using qemu you can emulate lots of platforms, even x86. But it would be pretty slow.
I think you should ask your brother how it was done.

Possible scenarios:
-qemu (slow, not easy to set up)
-slideshow (just prepare coupe of slideshows)
-movie
-vnc/rdp to another computer.

If you want a `full os` I would recommend Angstrom for it.
XP isn`t going to be any good.

Might have been Andromeda Debian's lxp-icewm, which is configured to look XP quite closely.

Thing that's slighty annoys me But that's a minor glitch, Andromeda really took fire back to my SL-C3100.

I have a multitude of PortableApps on the CF card and it would be a great convenience to use them on the Zaurus.

Since they are compiled for x86 (as is Windows XP) they won't work anyway.

For most programs that you might want to use, there is probably a program that works on the zaurus that can do the exact same thing. I have used multiple portable programs on an sd card when it is plugged into a computer, then used the same card in my zaurus. while the software I used was different, the files were the same, and it was very handy. Are there any specific programs you are wanting to use?