OS X’s Dock is a great way to organize the apps you use most commonly (as well as any others you might have open). But it can get cluttered quickly. MacOSXHints.com reader JamieF recently shared a Terminal command that could help you make some room by hiding an application’s Dock icon.
To implement this trick for Stickies, for example, open Terminal, then type defaults write /Applications/Stickies.app/Contents/Info LSUIElement 1. You can adapt that command to any other application by substituting its path and filename for /Applications/Stickies.app. To reverse the command, type the same command, but change the 0 to 1.
There’s just one catch with this tip: The LSUIElement setting affects not only the Dock icon, but also the application’s menu bar. That means that, while the setting is in effect, you won’t be able to access any of the app’s options that require that bar. You can still use keyboard shortcuts (so you can still, for example, get to the app’s preferences by pressing Command+comma. But you won’t be able to use any of the drop-down menus.