Heads Up is a trivia-style party game that was recently featured (and played) on The Ellen DeGeneres Show. With the game installed on just one iPhone, you can challenge a friend or several friends to a trivia competition. While you won't have much fun alone with Heads Up, it might be the perfect app for livening up a dinner party or family event.
The way it works is, you pick a trivia category from one of seven themed decks of "cards." These aren't actually trivia categories in the traditional sense; Heads Up combines trivia with identifying silly accents, humming music to guess a song, acting out an action (like classic Charades), and other fun activities.
When you're ready to play, you start the game and hold your iPhone facing outward so your friends can see the screen. An answer appears on the screen and it is your friends' job to give you clues without saying a word in the answer or anything that rhymes with it. You have 1 minute to solve as many cards as you can.
Since the holder of the iPhone should never look at the screen, Heads Up has accelerometer gestures for controlling the game. When you answer a card correctly, turn your iPhone face down to move on to the next card. When your friends have no knowledge of a particular card or you can't guess the answer, turn your iPhone face up to pass and move on to the next card.