iSamurai is a crazy two-player app that recreates real Samurai sword fighting without the flesh wounds or ritual disembowelment.

The app uses the iPhone’s built-in motion sensor and accelerometer to tell where the iPhone is in space and make noises that suggest that you are fighting with swords. It connects to another player’s iPhone with peer-to-peer networking and looks pretty goofy. Clearly the concept of fighting with invisible swords takes a bit of skill and imagination but it’s a fascinating use of all of the iPhone’s motion features. It’s available now for 99 cents.

The iPhone and iPod Touch have three accelerometers (devices which measure changes in speed and gravity). When a player swings his iPhone to attack, the iPhone senses the motion using its accelerometers and communicates that motion in real time over Wi-Fi to the opponent’s iPhone. If the opponent holds up his iPhone with the correct block for that attack, the ring of steel on steel is heard. Unsuccessful blocks result in a variety of sound effects indicating that an attack was successful. At no time do the iPhones come into actual contact with each other or with the opponent, but the iPhones know what is happening in the battle and simulate a real sword fight.

iSamurai: Two-Player Sword Fight includes the following features:
* Two-player interactive Wi-Fi game using two iPhones or iPod Touches
* Single-player game with four levels of difficulty
* Tutorial featuring animations of the different attacks
* Training “Dojo” where the player can practice the different iSamurai moves
* Art of War quotes from legendary warriors