Disable the menu option: ‘File ▸ Eject [volume]’ (cmd⌘ + E) in the Mac OS X Finder menubar.
10.8
Enable the debug menu in Disk Utility
OS X Disk Utility has a hidden debug-menu that, when enabled, can give you access to more advanced Disk Utility features. The debug-menu gives you access to the restore partition (OS X 10.7 and above). The ‘Debug’ option will appear after applying this command in OS X Terminal:
Enable the 2D Dock
If the 3D Dock isn’t your taste, you can use Terminal to switch to the 2D visual implementation.
Enable the secret settings in Twitter for OS X
The Twitter for Mac OS X application has a secret preferences tab. This gives you access to options like: Show full names, Compose windows float over all windows, type anywhere and munch more.
Enable hidden Stacks list view in OS X Dock
This terminal tweak will enable a hidden list view for your stacks that is way better then the default one that comes with OS X. Enable hidden Stacks list view with the following command:
Stop icons from bouncing in OS X Dock
When applications first open or need to alert the user of some new update, the icons in the dock bounce. Very helpful when you are multitasking, but some users find it distracting. Use following command to stop the icons from bouncing.
Disable ‘press and hold’ option in Mac OS X 10.7+
If you press and hold a letter in OS X, a pop-up will appear with the various accented versions of that letter. If you don’t use this and it bothers you, you can disable it.