Web Subject Guides
Compiled and categorized by people. Results lists are short and precise.
ipl2 -- Hosted by Drexel University and a consortium of colleges and universities.
The Scout Report Archives -- Maintained at the University of Wisconsin.
BUBL LINK -- Created and maintained in Great Britain.
DMOZ Open Directory Project -- Hosted by Netscape and maintained by volunteers.
Infomine -- Maintained by various universities in California (a subject guide to scholarly websites).