gistfile1.js

function createS3(){
  var bucket = new AWS.S3({
    params: {
      Bucket: 'backspace-cognito-test'
    }
  });
  //Object key will be facebook-USERID#/FILE_NAME
  var objKey = 'facebook-'+FACEBOOK_USER.id+'/test.txt';
  var params = {
      Key: objKey,
      ContentType: 'text/plain',
      Body: "Hello!",
      ACL: 'public-read'
  };
  bucket.putObject(params, function (err, data) {
    if (err) {
      errorMessage += 'putObject: ' + err + "_____";
      $('#errorConsole').text(errorMessage); // an error occurred        
    } else {
      message += "Successfully uploaded data to your S3 bucket" + "_____";      
      $('#appConsole').text(message);       // successful response        
    }
  });
}

The blog for this code is now maintained at http://blog.backspace.academy