"Phone a Friend" is a lifeline option used in the popular quiz show Who Wants to Be a Millionaire. Contestants can call a pre-selected friend or family member for help when they are unsure of an answer to a question. This lifeline allows them to seek advice and gain a different perspective, potentially increasing their chances of winning. The friend on the other end of the line has a limited amount of time to discuss the question and provide their thoughts. This feature adds an element of strategy and social interaction to the game, making it more engaging for both contestants and viewers.