I am posting this through Tiger using the latest Altivec build. Tiger is still slow, but it's a lot more useable than it was before. Tiger never seemed to like the .3 builds before, at least not on my system, but it seems to be agreeable with the latest Altivec build.
I can actually open up menus without having to wait 5 minutes for them to, well, actually open.
Tiger says I'm running on a 580 MHz G4 with 128 megs of RAM (I tried to add more RAM, but the system wouldn't boot at all, so I had to # the ram out.)