So, I've got an external hard drive with two firewire ports that I use for backups but I want to backup my other powerbook over a network connection. I was thinking that ip over firewire would be the fastest way to connect these two machines. The delimna I have is that on the AiBook I have a firewire 400 port and a firewire 800 port and on the Tibook I have a firewire 400 port. The external enclosure allows me to daisy chain firewire ports so perhaps I could plug in the other computer to that second port but I'm worried about doing that and I'm wondering if it's better to use the firewire 800 port as a second firewire 400 port from the computer. Presumably Apple make a cable that allows you to use the firewire 800 port with a firewire 400 device. I don't need a firewire hub as I have no other firewire devices.