title: Calculating usage of localStorage space
body: <p>I am creating an app using the Bespin editor and HTML5's localStorage. It stores all files locally and helps with grammar, uses JSLint and some other parsers for CSS and HTML to aid the user.</p>
  
  <p>I want to calculate how much of the localStorage limit has been used and how much there actually is. <strong>Is this possible today?</strong> I was thinking for not to simply calculate the bits that are stored. But then again I'm not sure what more is there that I can't measure myself.</p>