Updated list

Yahoo=Yahoo! Slurp
Yahoo! Germany=Yahoo! DE Slurp
Alexa=ia_archiver
AllTheWeb=crawler@fast
AllTheWeb=FAST-WebCrawler
AltaVista=Mercator
Altavista=Scooter
Amazon=AMZNKAssocBot
Anzwers=AnzwersCrawl
Ask.com=Ask Jeeves
Ask.com=teoma_agent1
Ask=Teoma
Atomz=Atomz
AskJeeves=AskJeeves
BecomeBot=BecomeBot
BoardReader=BoardReader
Boitho=boitho.com
Crawler.de=Crawler
DepSpid=DepSpid
DMOZ=Robozilla
Entireweb=Speedy Spider
Excite=ArchitextSpider
Exalead=Exabot
Factbites=Factbot
Fast=FAST
Fast(AllTheWeb)=FAST-WebCrawler
Fast(AllTheWeb)=crawler@fast
Gigabot=Gigabot
Google Adsense=Mediapartners-Google
Google Images=Googlebot-Image
Google Mobile=Googlebot-Mobile
Google=Googlebot
Google Sitemaps=Google-Sitemaps/1.0
Infoseek=InfoSeek sidewinder
InfoSeek=UltraSeek
Inktomi=Slurp
Kalooga=Kalooga
Looksmart=MantraAgent
LookSmart=FurlBot
Lycos=Lycos_Spider_(T-Rex)
MJ12bot=MJ12bot
MSN=MSNBOT
Microsoft Research=MSRBOT
MSN=MSNBOT
MSN Pic-Search=PSbot
Naver.com=Yeti/
NaverBot=NaverBot
NetSeer=Teemer
NorthernLight.com=Gulliver
noXtrum=noxtrumbot
Nutch=nutchsearch
Omgili=omgilibot
Pagebull=Pagebull
Picsearch=psbot
ScrubTheWeb=Scrubby
Searchme=Charlotte
Seznam=SeznamBot
Search Hippo=Fluffy the Spider
Shelob=shelob
SingingFish=asterias
Snapbot=Snapbot
SnapPreviewBot=SnapPreviewBot
Snoopy=Snoopy
Sogou=sogou web spider
StackRambler(ru)=StackRambler
StumbleUpon=StumbleUpon.com
TAMU.edu=IRLbot
Teoma=TeomaAgent
TMCrawler=TMCrawler
Twiceler=Twiceler-0.9
Voila=Voila.fr
Voila=Voila
Voila=VoilaBot
Voyager=Voyager
Walhello=appie
WebAlta=WebAlta
Webcrawler.com=WebCrawler
Whois.sc=SurveyBot
Wisenut=Zyborg
Worio=woriobot
YaCy=yacybot
YodaoBot=YodaoBot
Yahoo! Blogs=Yahoo-blogs/v3.9
Yahoo! MM=Yahoo-MMcrawler
Yoono=yoofind