I use a FireWire drive attached to an iMac G3 to house all my ripped DVDs and downloaded TV shows - sure beats USB 1!. I don't have the need for target disk mode all that often, but it has come in handy a time or two: I'm glad my 2006 iMac has the capability. And of course before the Flip era, I used FireWire to run video from the Handycam right into iMovie.