What I hate along this topic is finding some great prop, texture or whatnot that you might only use for one or two projects...but once you leave it in your folders for awhile it gets lost in the clutter. What I have started doing is using an install monitor [I use Norton Cleansweep] and monitor each installation. That allows me to then get rid of all instances and parts of a file or only remove what I want, without a manual search.