Add folder to Places sidebar in Mac Finder

Very simple, navigate to the folder you desire to have listed under Places in the Finder, select it and press Cmd+T. That's it!
To remove the folder from the list, right click it in the sidebar and select "Remove from sidebar".

Digital Color Meter in OS X

Digital Color Meter in OS X is a built in tool/application that comes with OS X and allows you to pick the color code for any color on the screen.

Replace multiple spaces/tabs with single space

Use following UNIX command to replace multiple spaces or tabs with a single space, thus enabling easier work with cut command:

tr -s ''