If I could pick a skill for everyone to learn it would be sign language. Sign language is a language that uses a system of manual, facial, and other body movements as the means of communication. This form is especially beneficial among deaf people. A method of communication, as between speakers of different languages, that uses hand movements and other gestures.
Some sign languages have obtained some form of legal recognition, while others have no status at all.
Signed codes of language can be useful for learning oral languages or for expressing and discussing literal quotations from those languages. They are generally too awkward and unwieldy for normal discourse. Exemplary of the mature status of sign language is the growing body of sign language poetry, and other stage performances.
Being a bilingual or trilingual expands your cognitive process when dealing with sign language communication.
Gestural communication for professional civic servants, such as firefighters, police officers, scuba divers and other professionals is beneficial to the recipient as well as the thoroughness that the signer conveys all complete information to the person.
You can be sure that nobody can overhear through doors. You will be comfortable knowing that you will not cause disturbances in libraries or church. You can engage in lively talk in noisy bars and discos where most of the time hearing someone directly beside of you is not possible.
Sign language has broken many barriers as the decades go by. Deaf people, mute people benefited from this training, placing them into society in productive manners. Other special needs which we have become more educated recently would be autism and asperger's syndrome. These forms of challenges have benefited by introducing sign language to the child to begin knocking down their communication barriers. They have their thoughts and feelings but haven’t learned to bring those expressions out for others to engage in conversation...