Known Wikipedia mirrors

\.answers\.com/
\.search\.com/
\.referenceencyclopedia\.com/
\.reference\.com/
\.wikipedia\.com/
\.wikipedia\.org/
\.mirrorpedia\.com/
\.brainyencyclopedia\.com/
\.babylon\.com/
\.bibleocean\.com/
\.digplanet\.com/
\.?medlibrary\.org/
\.allexperts\.com/
\.reference\.com/
\.feedbus\.com/
\.?pandapedia\.com/wiki/
\.?tubious\.com/
www\.pontefract-yfc\.co\.uk/wiki\.php
www\.territorioscuola\.com/wiki/
\.?otovaganza\.com/minicooper-old\.php
\.?net-encyclo\.com/en/
\.?prescriptiondrug-info\.com/
\.?wikivotr\.com/
\.?jgames\.co\.uk/title/
\.?allrss\.com/wikipedia\.php\?
india\.smashits\.com/wikipedia/
\.citizendia\.org/
\.?s2008\.info/
\.?moralnafirma\.pl/
\.?boopsie\.com/
www\.thepaleochorasite\.com/wiki/
\.fotopedia\.com/
\.?reachinformation\.com/define/
yomi\.mobi/egate/
pediaview\.com/
wikipedia\.7val\.de
www\.wikiwak\.com/
\.fiveafrica\.com/
\.freebase\.com/
\.juggle\.com/
\.barcodinglife\.com/
danpritchard\.com/wiki/
\.aadet\.com
www\.absoluteastronomy\.com/topics/
en\.goldenmap\.com/
\.maps\.thefullwiki\.org/
\.www\.askbiography\.com/
\.tutorgig\.info/ed/
\.wordiq\.com
\.mundoandino\.com/
english\.turkcebilgi\.com
\.tutorgigpedia\.com
uk\.ask\.com\/wiki
wpedia\.goo\.ne\.jp\/enwiki\/
\.amazon\.com\/wiki\/
\.scribd\.com\/doc\/55288486\/Diagnostic-and-Statistical-Manual-of-Mental-Disorders
www\.mashpedia\.com
hewgill\.com\/~greg\/wikiblame\/
encycl\.opentopia\.com\/term\/
\.thefullwiki\.org
wikipedia-update\.com
\.airports-worldwide\.com
wikipedia\.sfstate\.us
lyricsfreak\.com\/.+(\/|biography\.html)$
wiki\.verkata\.com
dbpedia\.org\/(resource|page)\/
readtiger\.com
\.cyclopaedia.net/

\en.scio.pw/

Known U.S. Government sites

\.gov/
\.mil/
countrystudies\.us/

Sites with CC-BY-SA-compatible contents

\.citizendium\.org/
\.?bhamwiki\.com/
\.?gardenology.org/
\.wikimedia\.org/
\.wikisource\.org/
\.wiktionary\.org/
\.wikia.com/
\.?planetmath\.org/
www\.libraryireland\.com/biography/
\.?appropedia.org/
www\.animalbase\.uni-goettingen\.de/zooweb/servlet/AnimalBase/?
www\.baseball-reference\.com/bullpen/
mnopedia\.org
(www\.)?newadvent\.org\/cathen\/
en\.wikipilipinas\.org
mspong\.org\/picturesque\/
judgepedia\.org\/
sourcewatch\.org\/
sgwiki\.com

Sites with explicit permission

www\.interface1\.net/
\.govtrack\.us/
www\.patents\.com/us