Just to say, i haven't had some time to try anything since the last post, had to do some RL stuff instead.
No distribution with current mainstream software will work decently on that PC. Your problem will be the memory, not the CPU: for example one of the most essential type of programs today, web browsers, are huge memory hogs. To make things worse, in linux the two main "desktops", Gnome and KDE, are also very fat in their recent versions, and even an old Gnome2 will probably be unusable. Even the supposedly "lightweight" window managers have become bloated. You'd need at lest some 400MB of memory.
I think there's recently been a trend to change some distros to LCFE...LFX...er...whatever, some other window manager (i'm not a linux person), which doesn't use that much memory.
But yeah, the memory is a problem. Just checked, my FF3 here already uses 100 MB ram, that doesn't look too promising.
Maybe some mobile version will do it.
I just happened to run across the description of the latest Lubuntu, apparently released this week. According to the wiki, it will run (slowly but successfully) on a P-2, 128MB machine. The download for the "alternate install" ISO (used if the machine has less than 384MB of RAM) is 592MB in size.
http://cdimages.ubuntu.com/lubuntu/releases/11.10/release/
http://cdimages.ubuntu.com/lubuntu/releases/11.10/release/lubuntu-11.10-alternate-i386.iso
I think i saw that too, bu the download of the image scares me a bit.
Will have to check the HDD size of that old computer (and the computer i'm currently sitting on

).
I don't know what is your goal with that old PC, but you might want to consider simply using an old version of Linux (try an old OpenSuse install CD, something like 10.2). But not if it's meant to be a permanently networked computer (bugs/security holes).
I'm not really sure what the point of using a PC that old/slow is, I regularly see first-gen dual-core PCs in the 2-GHz range getting junked. At that range, they'll probably be light on the RAM, but you can easily get a PC of that age and stick in 4GB RAM for well under $100.
I'm currently a student and probably in 2 months unemployed for i-have-no-idea-how-long, so spending money for something which is not really needed is not an option.
Besides that, that PC is not really meant to be used for something productive.
I just want to have some backup in case any of the other computers here has some problems, and maybe something to play around a bit with. Thought i might take some deeper views into linux...at least to deal a bit more with it. It's a bit embarrassing to be a computer scientist and having no real clue about linux

.
I might also want to change system at which i'm currently sitting (P3 866 Mhz, 256 MB RAM, 8 GB hardrive; no, NOT my gaming machine) to something else besides WinXP (yes, it's slow as hell), but not unless i have something else with which i can access the internet (...without getting in conflict with any of my family members, i mean

; working machines are enough here, but they are not necessarily free).
If i wanted to have some real pain, i'd use the P133 behind me instead

.