If you want to give it a spin, get the Live CD so you can actually see if Ubuntu will work on your machine. This will tell you if all appropriate drivers are in place. I keep a stack of different distros because some work better on different systems, and some don't work at all. Just be aware that the live cd will be a little slow (even on a newer machine) because the OS is reading off the CD.
A PII with 192Megs Ram might be a little underpowered for Ubuntu 10.4. I am running it on a no-name laptop that originally came with Vista. It really makes this thing shine, but it has a P4 equivalent with 1.5GB RAM. No probs with any hardware, including the internal wireless card (don't even know what it is).
Using 10.4 on a homebuilt P4 desktop too and no hitches there either.
I am also running the current distro of Linux Mint on an old Dell C400 (PIII with 512 MB RAM). Mint has four different versions in their current distro lineup, with different desktop environments, and some of these are very light (don't take up a lot of system resources).
I hate to toss anything, and have an old Tecra 8000 with a PII. I have tried a few things on it, but the best ones so far are TinyME, Puppy and DSL.
When you find one that works well with your hardware, please share your experiences here. Thanks.