Search Engines... Simple as that.
Member of the Internet Link Exchange
HotBot:
all the words
any of the words
the phrase
the person
the URL
Excite:
Alta Vista:
Lycos:
Infoseek:
Webcrawler:
Open Text:
any of these words:
all of these words:
this exact phrase:
Yahoo:
The Amazing Metacrawler:
(multiple engines)
All4One (Great Metasearch):
411:
Link Star:
Savvy: