title: Plotting pca biplot with ggplot2
body: <p>I wonder if it is possible to plot pca biplot results with ggplot2. Suppose if I want to display the following biplot results with ggplot2</p>
  
  <pre><code>fit &lt;- princomp(USArrests, cor=TRUE)
  summary(fit)
  biplot(fit)
  </code></pre>
  
  <p>Any help will be highly appreciated. Thanks</p>