No one single process can use more than 4GB at a time, but you can fit two processes using 4GB in 8GB of RAM.
(The kernel goes into 64-bit mode to set up the virtual memory. This is the only part of Panther where 64-bit addressing is directly used)
No it won't. Not unless you install Linux/ppc64.
I don't see how Windows could do it either unless you were using x86-64, because it's still impossible to address over 4GB no matter what kind of 32-bit CPU you have.
Now it's even better!
http://www.bloodandcoffee.net/feanor/kilonet.html
http://www.bloodandcoffee.net/feanor/kilonet-logs/
Now, where'd xoot go... he seems to have disappeared entirely off the Net...