There is however a few things you can do. First, open the Spotlight preferences in System Preferences and disable everything you don’t care about. I never search for fonts for example, so I always disable that. The key here however is to make sure Applications are at the top of the list.

While you certainly knew about this first tip, you might not know about the second one. Other than filename and content, Spotlight also searches each file’s metadata and one that always exists and is accessible through the Finder is the “Spotlight Comments” field where you can type anything you want.

For the apps you use the most, find their icons in the Finder and type CMD-I to open the Get Info panel. There, you’ll find the Spotlight Comments field. The key here, is to add something unique to make the search fast. I suggest adding “aa” in front for application followed by a few letter. Firefox for example could be aaf. You can then “Cmd-Space” to open spotlight followed by your 3-4 letters abbreviations (“aaf”) followed by enter. The search is almost instant!

This unfortunately doesn’t work with system apps in 10.6 since those are locked when using the Finder. If you have PathFinder, you can actually change them from there.