The Barcode Scanner app
You can easily find this app on the Android Market. To use it, nothing could be simpler. Just click on the app and a mode similar to the camera will open, except that a red bar flashes in the middle of the screen. You must then place this red bar over the entire code to be read, trying to remain as still as possible. After a few seconds, the application will decipher the code and offer you to go on the internet or will display text following what the code means.