PhoneyTools

var helper = new InstaPaperHelper(userName, password);
helper.AddToInstaPaperAsync(
  new Uri("http://phoney.codeplex.com"), 
  "PhoneyTools",
  success =>
  {
    if (success) MessageBox("Added to InstaPaper!");
  });

// OR Use the Static Version

InstaPaperHelper.AddToInstaPaperAsync(
  userNameBox.Text, 
  pwdBox.Password, 
  new Uri("http://phoney.codeplex.com"), 
  "PhoneyTools",
  success =>
  {
    if (success) MessageBox("Added to InstaPaper!");
  });