Research Links:

A9.com
About.com
Browse by topic
AlltheWeb
Answers.com
Ask.com (Teoma)
Bing
Clusty (Vivisimo)
Queries several top search engines, combines the results and generates an ordered list
Dogpile
Meta-search engine, searching all the most popular engines and retrieving the best combined results
GigaBlast
Google
HotBot
INFOMINE
A virtual library of Internet resources relevant to faculty, students and research staff at the university level. It contains useful resources such as databases, electronic journals, electronic books, online library card catalogs, directories of researchers and many other types of information.
Internet Public Library
The iSchool at Drexel, College of Information Science and Technology
Librarian's Index to the Internet
A table containing multiple search engines
LibrarySpot.com
Several reference desk sources
Lycos
Refdesk.com
Reference Center and General Government
USA.gov
Rollyo
An easy way to create personal search engines using the sources you trust
Search Engine Colossus
International directory of search engines
Twingine
Run a Google and Yahoo search simultaneously
Yahoo