One of the biggest advances in Spotlight is that it will be able to search remote computers. This is a big deal for home users, who have different files -- think digital photos and music -- stored on different Macs. You'll be able to search across all the Macs in your house for that one photo that you know you downloaded from your camera but can't find or for the particular CD track you ripped but don't remember on which of three Macs you placed it.