Change Network Location Quickly in Mac OS X via Apple Menu
Network Locations in Mac OS X allow you to save specific configurations and settings for different networks. Once they’re setup, you can use them to change between various network configurations quickly, without having to re-enter any settings. These are perfect if you are switching between things like an automatic DHCP config vs a manually assigned IP address, different routers with unique settings at different locations, toggling proxy use on or off, using different and specific DNS configurations, or just have custom network configs for specific places like work, home, or school.






Ever needed to quickly mirror a Mac display, switching another screen from an extended desktop to the mirrored image of what’s on the primary screen? Sure, you can visit the System Preference Display panel and fumble around in settings, but there is a much easier and faster way to toggle display mirroring with just a simple keyboard shortcut.
iOS devices can use an optional 

The iPhone is easily one of the best pieces of technology ever invented, but let’s just go ahead and admit that nothing is perfect. There are a few default settings on the iPhone that are just plain annoying, but within just a minute or two you can fix all of that with a handful of simple adjustments, and have a much better experience.
Certain situations require a Mac to be booted from an external boot volume, rather than the primary startup disk. There are plenty of reasons for booting from external volumes, whether it’s to troubleshoot problems, repair disks, 

