From the very start, directories have served a very useful purpose on the Internet. (One I find useful for example is Free Web Directory). News sites can also be considered directories: they index and categorize news stories! What about categorizing software? In the open source world you get Savannah, SourceForge, Freshmeat; there are still, believe it or not, shareware and freeware directories like FileBuzz, PCWin Download Center and Freeware Downloads (although you need to be careful, as they are not like their free-as-in-freedom counterparts).