The 4400: Body Duplication

After becoming promicin-positive himself due to being infected by a promicin-inducing virus, Jed Garrity unconsciously created a fully-clothed, self-aware duplicate of himself.

Limitations
The copies that are created through this ability are completely identical to each other, so much so that neither is able to tell whom is the original. Other copies are only able to be created after one dies, doing so in a safer environment. When one of these copies does die, the other existing copy experiences the trauma, but the replacement doesn't retain any instant knowledge of it.