Said PCLOS runs fine on a PIII 600 or so, but has a touch more stuff loaded and eye candy on that I might want for a slower machine. It might be nice if that's turned off, but I don't know for sure.
You should also look into Zenwalk (Slackware-based). Zenwalk + KDE (for apps, mainly

) aught to do quite well.
Basically, 192MB gives some room to work in, but using a 366, it wouldn't hurt to go a bit more minimal than Ubuntu.