Remove Duplicates from the Open With Right-Click Menu in Mac OS X.
# Remove Repeat App Entries in "Open With" Menu of OS X
$ /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/LaunchServices.framework/Versions/A/Support/lsregister -kill -r -domain local -domain user;killall Finder;echo "Open With has been rebuilt, Finder will relaunch"
# Same command string broken into multiple lines:
$ /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/\
LaunchServices.framework/Versions/A/Support/\
lsregister -kill -r -domain local -domain user
# alias it
alias fixow='/System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/LaunchServices.framework/Versions/A/Support/lsregister -kill -r -domain local -domain user;killall Finder;echo "Open With has been rebuilt, Finder will relaunch"'