title: Converting spatial polygon to regular data frame without use of gpclib tools
body: <p>I working with spatial data in R for a commercial application and would like to use ggplot2 for data visualization. If you run the Hadley's example at <a href="https://github.com/hadley/ggplot2/wiki/plotting-polygon-shapefiles" rel="noreferrer">https://github.com/hadley/ggplot2/wiki/plotting-polygon-shapefiles</a> you find that in order to run the <code>fortify</code> command you need to enable the use of gpclib tools using <code>gpclibPermit()</code>. </p>
  
  <p>I'm looking for an efficient way (that doesn't involve manually hacking into the S4 object) to perform the same operation that <code>fortify</code> does here, i.e. take a spatial polygon object and turn it into a regular data frame where row entries contain latitudinal and longitudinal coordinates along with a polygon id. </p>
  
  <p>Has anyone else solved this one? </p>