Also, if using WiFi be certain to setup proper user logins and passwords for everyone on your machine - do not allow any public access. You could be asking for trouble on a wireless network if you're in an apartment building or other urban location. I'd also suggest only turning sharing on when you actually need it to copy files, then turn it off when done. Not only will this make things more secure, it will give you better performance on the Mac.

You can double check, but I know Powerbooks automatically detect the ethernet connection so you don't need a cross over cable, just a regular cable will be fine.

Even 802.11g, aka airport extreme is not anywhere near the 54MBps that is advertised. You'll get much better results with a hard cable between the 2 machines.

I was wondering whether Mac OS X had that installed per default
or not, now I know. Thanks Boyd!