If you are more of a visual person and would like to organize your folders and files using different colors, than check it out how to use color labels in Mac OS X.
You can visually insert a radio button into your form and set its properties. Use radio buttons when you want users to select only one choice from a set of options.
This well kept secret surfaced just recently. All Apple devices running iOS 7 have a pretty darn well hidden Easter egg. Just follow this step-by-step instructions carefully and the very first Mac OS version 1 will appear on your iPhone or iPad. How freaking awesome is that?