NowWhat is a planet in the Whole Sort Of General Mish Mash formerly known as the Hitchhiker's Guide universe. NowWhat can be found in place of planet Earth at an unlikely position along the probability axis, in an alternate universe.
According to the novel Mostly Harmless, "the planet of NowWhat had been named after the opening words of the first settlers to arrive there after struggling across light-years of space to reach the furthest unexplored outreaches of the Galaxy. The main town was called OhWell". The president of NowWhat had shot himself, and a picture that was taken shortly after hangs as a greeting for travellers in the planet's airport.
The only export of NowWhat is the NowWhattian boghog skin, which no one in their right minds would want to buy because it's thin and very leaky, and the export trade only manages to survive because of the significant number of people in the Galaxy who are not in their right minds. In fact, one of the lingering questions on NowWhat is how the boghogs manage to stay warm in their skins. It says, "if anyone had wanted to learn the language of the boghogs, they would have discovered that they don't and are just as cold and miserable as everyone else". It also mentions that no one wanted to, because the boghogs communicate by biting each other very hard on the thigh.
Travellers who arrive on NowWhat are greeted by a picture of the president smiling a ghastly smile; the picture was taken after he shot himself, and the missing corner of his face had been drawn in crayon. Everyone there pursues one ambition: to leave.
Arthur Dent arrives on NowWhat in search of Earth. After turning the map upside down and adjusting for different sea levels, he discovers that the shapes of the continents of NowWhat resemble those of the planet Earth. For lack of any other similarity, Arthur Dent concludes that it is the right planet but the wrong universe and leaves again.