Duck Duck !Bang

!Bang

!amazon bags searches Amazon.com for bags, directly. We call this search syntax "!bang", and it works for 100s of sites:

Most big sites work, e.g. !youtube
Most generic keywords work too, e.g. !images
There are also shorter versions, e.g. !g !i !yt
Just '! ' will take you to the first result.

Here's the full list of !bang keywords by category:

Tech

Blogs: !alistapart !arstechnica !arturogoga !boingboing !cnet !engadget !gawker !gigaom !gizmodo !lifehacker !mashable !readwriteweb !slashdot (!/.) !techcrunch !techdirt !tomshardware !valleywag !wired !zdnet
Companies: !adobe !apple !dell !hp !ibm !lenovo !microsoft (!ms) !netgear !nvidia
Design: !forrst
Downloads: !bitbucket !btjunkie !freshmeat !github !isohunt !macupdate !shareware !software !sourceforge !thepiratebay (!tpb) !torrent !torrentz !versiontracker
Languages (adobe): !as3 !flex
Languages (c++): !boost !cpp !parashift
Languages (d): !d
Languages (erlang): !cean
Languages (haskell): !hackage !hoogle
Languages (java): !jdk
Languages (javascript): !jquery !mootools (!moo) !yui
Languages (lisp): !lisp
Languages (perl): !cpan !permonks !perldoc
Languages (php): !php
Languages (python): !django !python !pypi !pylons !sqlalchemy
Languages (ruby): !rails !ruby !rubydoc !rubygems
Languages (other): !ctan !sas
Libraries/Frameworks: !android !appengine !drupal !drupalapi (!dapi) !latex !qt
Programming: !activestate !appledev !man !code !developpez !dotnet (!.net) !launchpad !mdc !msdn !rfc !so !stackoverflow (!so) !technet !w3c !w3schools !zvon
Startups: !alexa !compete !crunchbase !msmvps !quantcast !whois
Sysadmin (network): !asn !dig (!host) !dns !ping !port !rbl !rdns !traceroute !serverfault (!sf) !superuser (!su)
Sysadmin: !archlinux !archaur (!aur) !archpkg (!apackages) !archwiki !dbugs !dpackages !distro !distrowatch !fports !iso !lxr !mysql !oracle !postgresql !ubuntuforums (!ubuntuf) !upackages

Online Services

Jobs: !careerbuilder !jobs !linkup !monster
Google: !google (!g) !gpat !gnz !googleuk (!guk) !gimages (!gi) !gvideos (!gv) !gmaps (!gm) !gbooks (!gb) !gnews (!gn) !gshopping (!gs) !gfinance (!gf !stock) !gtranslate (!gt) !gscholar (!gsc) !greader (!gr) !ggroups (!gg) !gdocs (!gd) !gphotos (!gp) !gblogs !gmail
Search: !ask !baidu !bing !clusty !yahoo !walpha (!wa !wolfram)
Search (Real-time): !evri !lavva !kurrently !oneriot !scoopler
Social: !facebook (!fb) !twitter (!tw) !43things !fotolog !friendster !ggroups !hi5 !myspace !orkut !skyrock !wink !xanga
Social news/links: !delicious !digg !metafilter !reddit !searchyc (!newsyc !hn) !newsvine
Tools: !bmaps !cache !downfor !local !map !gmap !proxy !tinyurl !translate !wayback (!archive)
Tracking: !capost !dhl !fedex !ups !usps !tnt

Multimedia

Docs: !ipernity !scribd !slideshare
Images: !bimages !clipart !deviantart !flickr !gimages !icons !images !istockphoto !gettyimages !photobucket !pictures !shuttershock !stockphotos !texture !wallpaper !yimages
Music: !allmusic !chords !concerts !deezer !imeem !itunes !lastfm !lyrics !metrolyrics !mp3 !musicbrainz (!mb) !podcast !pollstar !rdio !ringtones !skreemr !tabs (!gtabs !btabs) !thumbplay !tones
Video: !youtube !crunchyroll !dailymotion !perfspot !truveo !veoh !video (!watch)

News

Aggregators: !ap !binsearch !blogs !news !newsnow !newsmax !nzbmatrix (!nzb) !reuters
Business: !bloomberg !businessweek !cnbc !fool !forbes !ft !wsj
Broadcast: !abcnews !bbc !cbsnews !cnn !msnbc !foxnews !npr !pbs
International: !globeandmail !redtram !smh !suntimes !thestar
Magazine: !csmonitor !economist !newsweek !newyorker !salon !slate !thenation
Newspaper: !ajc !chicagotribune !guardian !latimes !mercurynews !newsday !nypost !nyt !sfgate !startribune !usatoday !washingtonpost
Specialty: !digitalspy !huffingtonpost !fark !nationalgeographic
Weather: !accuweather !weather !weatherbug !wunderground

Entertainment

Blogs: !tmz !perezhilton !theonion
Movies: !imdb !netflix !rottentomatoes (!rt) !metacritic !opensubtitles (!osub) !showtimes !subscene !tmdb
Events: !eventful !upcoming !stubhub !tickets !ticketmaster !yelp
Games: !cc !cheatcc !cheatcodes !ign !gamecheats !gamefaqs !gamepro !gamesradar !gamespot !miniclip
Sports: !cbssports !espn !mlb !nba !nfl !nhl !si
TV: !cartoonnetwork !discovery !disney !mtv !tv !tvguide !tvtropes

Research

Learning: !answers !allexperts !howstuffworks !howthingswork !instructables !whatis !wikipedia (!w !wiki !wen !wde !wfr !wit !wpl !wnl !wpt !wru !wes !wja) !wikitravel (!wikit)
Government: !cspan !entrez !irs !loc !pubmed !sba !sec !usa
Reference: !about !acronyms (!acro) !anagram !bartlets !bible !biblegateway !biography !britannica !define !dictionary !encyclopedia !etymology !freedict (!fd) !genesis !gigapedia !leo !nciku !pdf !perseus !quotes !rae !rhyme !synonyms !thesaurus !urbandictionary !wiktionary !wordnet !wordreference
Topical: !allrecipes !epinions !forkd !mathworld !recipes !scholar (!gsc) !summitpost !veroot !webmd
Travel: !expedia !gorp !tripadvisor

Shopping

Big box/department: !costco !ikea !jcpenny !macys !target !walmart
Online: !allposters !amazon (!a) !bookfinder !buy !ebay !overstock !posters !price !shopping (!shop) !shopzilla
Services: !coupons !parking !traffic
Tech: !bestbuy !circuitcity !digikey !domain !godaddy !mouser !newegg !octopart !pricegrabber

And here's the full list alphabetically:

!43things
!abcnews
!about
!accuweather
!acronyms (!acro)
!activestate
!adobe
!ajc
!alexa
!alistapart
!allexperts
!allmusic
!allposters
!allrecipes
!amazon (!a)
!anagram
!android
!answers
!ap
!apackages
!appengine
!apple
!appledev
!archaur (!aur)
!archlinux
!archpkg
!arckwiki
!arstechnica
!arturogoga
!as3
!ask
!asn
!baidu
!bang
!bartlets
!bbc
!bestbuy
!bible
!biblegateway
!bimages
!bmaps
!bing
!binsearch
!biography
!bitbucket
!blogs
!bloomberg
!boingboing
!bookfinder
!boost
!britannica
!btjunkie
!businessweek
!buy
!cache
!capost
!careerbuilder
!cartoonnetwork
!cbsnews
!cbssports
!cc
!cean
!cheatcc
!cheatcodes
!chicagotribune
!chords
!circuitcity
!clipart
!clusty
!cnbc
!cnet
!cnn
!code
!compete
!concerts
!costco
!coupons
!cpan
!cpp
!crunchbase
!crunchyroll
!csmonitor
!cspan
!ctan
!d
!dailymotion
!dbugs
!deezer
!define
!delicious
!dell
!developpez
!deviantart
!dhl
!dictionary
!dig (!host)
!digg
!digikey
!digitalspy
!discovery
!disney
!distro
!distrowatch
!django
!dns
!domain
!dotnet (!.net)
!downfor
!dpackages
!drupal
!drupalapi (!dapi)

!ebay
!economist
!encyclopedia
!engadget
!entrez
!epinions
!espn
!etymology
!eventful
!evri
!expedia
!facebook (!fb)
!fark
!fedex
!flex
!flickr
!fool
!forbes
!forkd
!forrst
!fotolog
!foxnews
!fports
!freedict (!fd)
!freshmeat
!friendster
!ft
!gamecheats
!gamefaqs
!gamepro
!gamespot
!gamesradar
!gawker
!gblogs
!gbooks (!gb)
!gdocs (!gd)
!genesis
!gettyimages
!gfinance (!gf !stock)
!ggroups (!gg)
!gigaom
!gigapedia
!gimages (!gi)
!github
!gizmodo
!globeandmail
!gmail
!gmaps (!gm)
!gnz
!gnews (!gn)
!greader (!gr)
!godaddy
!google (!g)
!googleuk (!guk)
!gorp
!gpat
!gphotos (!gp)
!gscholar (!gsc)
!gshopping (!gs)
!gtranslate (!gt)
!guardian
!gvideos (!gv)
!hackage
!hi5
!hoogle
!howstuffworks
!howthingswork
!hp
!huffingtonpost
!ibm
!icons
!ign
!ikea
!images
!imdb
!imeem
!instructables
!ipernity
!irs
!iso
!isohunt
!istockphoto
!itunes
!jcpenny
!jdk
!jobs
!jquery
!kbugs
!kurrently
!lastfm
!latex
!latimes
!launchpad
!lavva
!leo
!lenovo
!lifehacker
!linkup
!lisp
!loc
!local
!lyrics
!lxr

!macupdate
!macys
!man
!map
!mashable
!mathworld
!mdc
!mercurynews
!metacritic
!metafilter
!metrolyrics
!microsoft (!ms)
!miniclip
!mlb
!monster
!mootools (!moo)
!mouser
!mp3
!msdn
!msmvps
!msnbc
!mtv
!musicbrainz (!mb)
!myspace
!mysql
!nationalgeographic
!nba
!nciku
!netflix
!netgear
!newegg
!news
!newsday
!newsmax
!newsnow
!newsvine
!newsweek
!newyorker
!nfl
!nhl
!npr
!nvidia
!nypost
!nyt
!nzbmatrix (!nzb)
!octopart
!opensubtitles (!sub)
!oneriot
!oracle
!orkut
!overstock
!parashift
!parking
!pbs
!pdf
!perezhilton
!perfspot
!perldoc
!permonks
!perseus
!photobucket
!php
!pictures
!ping
!podcast
!pollstar
!port
!posters
!postgresql
!price
!pricegrabber
!proxy
!pubmed
!pylons
!pypi
!python
!quantcast
!quotes
!qt
!rails
!rae
!rbl
!rdio
!rdns
!readwriteweb
!recipes
!reddit
!redtram
!reuters
!rfc
!rhyme
!ringtones
!rottentomatoes (!rt)
!ruby
!rubydoc
!rubygems

!salon
!sas
!sba
!scholar
!scoopler
!scribd
!searchyc (!newsyc !hn)
!sec
!serverfault (!sf)
!sfgate
!shareware
!shopping (!shop)
!shopzilla
!showtimes
!shuttershock
!si
!skreemr
!skyrock
!slashdot (!/.)
!slate
!slideshare
!smh
!software
!sourceforge
!sqlalchemy
!stackoverflow (!so)
!startribune
!stockphotos
!stubhub
!subscene
!summitpost
!suntimes
!superuser (!su)
!synonyms
!tabs (!btabs !gtabs)
!target
!techcrunch
!techdirt
!technet
!texture
!thenation
!theonion
!thepiratebay (!tpb)
!thesaurus
!thestar
!thumbplay
!ticketmaster
!tickets
!tinyurl
!tmdb
!tmz
!tnt
!tomshardware
!tones
!torrentz
!torrent
!traceroute
!traffic
!translate
!tripadvisor
!truveo
!tv
!tvguide
!tvtropes
!twitter (!tw)
!ubuntuforums (!ubuntuf)
!upackages
!upcoming
!ups
!urbandictionary
!usa
!usatoday
!usps
!valleywag
!veoh
!veroot
!versiontracker
!video (!watch)
!w3c
!w3schools
!wallpaper
!walmart
!walpha (!wa !wolfram)
!washingtonpost
!wayback (!archive)
!weather
!weatherbug
!webmd
!whatis
!wiktionary
!whois
!wikipedia (!w !wiki !wen !wde !wfr !wit !wpl !wnl !wpt !wru !wes !wja)
!wikitravel (!wikit)
!wink
!wired
!wordnet
!wordreference
!wsj
!wunderground
!xanga
!yahoo
!yelp
!yimages
!youtube
!yui
!zdnet
!zvon

If you'd like to add something, please let me know!