This article explores the practice of “beeping” or “missed calling” between mobile phone users, or calling a number and hanging up before the mobile’s owner can pick up the call. Most beeps are requests to call back immediately, but they can also send a pre-negotiated instrumental message such as “pick me up now” or a relational sign, such as “I’m thinking of you.” The practice itself is old, with roots in landline behaviors, but it has grown tremendously, particularly in the developing world.