title: Adding an extra point in a ggplot2 graph
body: <p>I have created a plot of the Sepal.Length and the Sepal.Width (using the iris dataset) with ggplot2.</p>
  
  <pre><code>  ggplot(iris, aes(x = Sepal.Width, y = Sepal.Length, col = Species)) + geom_point()
  </code></pre>
  
  <p>Works fine but now I would like to add a seperate point to the graph with a blue color. So for example:</p>
  
  <pre><code>  df = data.frame(Sepal.Width = 5.6, Sepal.Length = 3.9) 
  </code></pre>
  
  <p>Any thoughts on how I can accomplish this?</p>