Open applications in the background in OS X, I don't want my focus taken from me. Respect my Focus!
To launch an app in Finder in the background (hidden) you can use a simple Automator service. Open Automator app, select a service that accepts files or folders in Finder and add a Run Shell Script action with following contents:



for f in "$@"
do
    open "$f" --hide
done


Save the service as Open in background. Open System Preferences./ Keyboard / Shortcuts / Services, find your new service and assign a keyboard shortcut you desire. I chose a handy ShiftCmdB. Close System Preferences and test the service and the shortcut.



Nice thing about this is that it works with apps as well as documents.