These sites provide links to directories of home pages of colleges and universities throughout the United States.

Scholarstuff.com: Links to colleges and universities around the world. Also has a graduate school directory and other useful information for college students.

Community College Web: This site contains a searchable index to the web sites for 1131 community colleges in the United States, Canada, and elsewhere around the world. 

U.S. Universities by State: a directory on the University of Texas web site

Integrated Publishing's
Large List of Colleges and Universities in the US

A site called the Internet Scout Project (from the University of Wisconsin at Madison) is a particularly useful site for people in education, especially students doing research. Information and resources are divided into categories including Business and Economics, Science and Engineering, and Social Sciences. A paragraph from the home page describes the site:

Surf smarter, not longer. Let the Internet Scout Project show you the way to the best resources on the Internet – then you can choose what’s best for you. Librarians and educators do the filtering for you, reading hundreds of announcements each week looking for the on-line resources most valuable to the education community