Abika -
Any Student -People search for college students.
AnyWho -AT&T toll free, tell, fax, email. 90 million consumer listings.
Bigfoot -Advanced people search.
DocuSearch -DMV, telephone, criminal, etc.. 
IAF -Internet Address Finder, smaller email directory.
IQ Data -Sec's states, county, criminal, civil, UCC, tax lien, judgment, federal & bankruptcy.
InfoSpace -The best people finder, white pages, reverse lookup.
nfoUSA -Find people.
KnowX -Public records, assets, etc.
LostPeople -Asset search, criminal records, FBI files.
Switchboard -People, address search  engines, phone numbers. 
Tel -Telephone directories of the web
Whitepages.com -Phone directory with free people search
WhoWhere? -From Lycos. Look for people, celebrities. 
World Email -World Email Directory. 
Yahoo -People search.
Zaba Search -People search.