Three vague story ideas which for lack of time and talent I will probably not write: During a 17th century plague quarantine, the residents of each home are expected to appear daily at a window and proclaim their condition to the inspector outside, after which they receive supplies according to their number. As members of a family die, they are played by other members of the family, so as to continue receiving the same amount of food and medicine. Over time, their identities blend together. The character of this blending should be ambiguous, reflecting the ambiguous character of the motivations underlying their charade: familial psychodynamics, especially sibling jealousy, and a self-interest which is understandable but perhaps not justifiable.
A marketing promotion for a celebrity news website allows people to cut-and-paste celebrity features into collaged portraits: the eyes of one, chin of another, & cetera. But inside the computer, those celebrity amalgamations are sentient, and become aware that their "life" is dictated by site users' whims -- and each time one of their features changes, so does their character. Piece by piece they become someone else altogether, which after all is how celebrity culture seems to affect its participants.
People can be pharmacologically or genetically altered to not need sleep, but as a result their lives are shortened by a third. Relationships between people of different sleep states are possible but difficult, just as relationships between people of radically different ages are now. One partner must accept that the other will die far sooner, or later. They can share a bed, but one will always lie there, awake.
Image: Børre Sæthre, "Stealth Distortion (...must have seen it in some teenage wet dream)"; photographed by Matthew Septimus [link]