I have a unibody 15" MBP, which, as you probably know, has a firewire 800 port. I have a couple of firewire 400 cables, but I don't actually have any firewire devices. That said, I have used firewire in the past for target mode, and I've definitely found it useful. At first I was going to buy an adapter, like this one. Now, I'm assuming that if I plug an adapter into a firewire 400 cable, it'll still run at firewire 400 speed, right (just like a UBS 1.1 cable runs at USB 1 speed even if plugged into two USB 2.0 ports) But then I saw this item, which is actually cheaper. That cord would be able to plug into the Firewire 800 port on my MBP, and the firewire 400 port on my iMac, right? In that case, it won't run at Firewire 800 speed, right? Because isn't the iMac hardware limited to firewire 400 speed? Also, what's the difference between the above mentioned cord and this one? Is this one for connecting devices instead of another computer? Are there any devices that I WOULD be able to plug in using the first cable?