launchtl can be used to disable and re-enable crash reporting or mDNSResponder or services mac os x

launchtl can be used to disable and re-enable crash reporting.  

To disable crash  reporting:

           launchctl unload -w /System/Library/LaunchAgents/com.apple.ReportCrash.plist
           sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.ReportCrash.Root.plist

     To re-enable crash reporting:

           launchctl load -w /System/Library/LaunchAgents/com.apple.ReportCrash.plist
           sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.ReportCrash.Root.plist

Disable mDNSResponder

sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist

Disable  Apple Push Notification Service (apsd) on OS X 10.8

launchctl unload -w /System/Library/LaunchDaemons/com.apple.apsd.plist