Misc. Search Sites:

https://www.peoplesmart.com/
http://www.spokeo.com
http://www.pipl.com
http://www.peekyou.com/
http://www.ipeople.com
http://www.yasni.com
http://www.skipease.com
http://www.peekyou.com
http://www.soople.com
http://Abika.com
http://freeality.com
http://radaris.com
http://www.isearch.com/
http://www.keotag.com/
http://yahoo.intelius.com/
http://www.findermind.com/free-people-search-engines/
http://www.192.com/ (UK)
http://www.phoneebook.co.uk/ (UK)
http://exifdata.com/ (viewing information behind a picture)
http://verify-email.org/
WhitePages Search:

http://www.whitepages.com
http://www.zabasearch.com/
Archives Search:

http://aad.archives.gov/aad/series-list.jsp?cat=GS29
http://www.archive.org/web/web.php
Social Network Searches:

http://www.facebook.com/directory/people/
http://topsy.com/
http://monitter.com/ (Monitor twitter convos)
http://socialmention.com/
http://knowem.com/
http://twoogel.com/
http://www.yacktrack.com
http://www.samepoint.com/
http://www.whostalkin.com/
Passwords!:

https://haveibeenpwned.com/
https://www.hacked-db.com/
http://www.hashkiller.co.uk/md5-decrypter.aspx
Phone Information & Lookups:

http://www.freecellphonedirectorylookup.com
http://www.numberway.com/
http://www.fonefinder.net
http://www.infobel.com
Public & Criminal Records Search:

http://publicrecords.onlinesearches.com
http://www.jailbase.com/en/sources/fl-lcso/
IP Address:

http://whatstheirip.com
http://resolver.in/resolve (skype2IP + IP2skype)
http://resolvethem.com/ (another resolver)
https://www.hanzresolver.com/ (a third resolver)
http://ipaddress.com/ (IP lookup)
Website:

http://who.is