title: Clipboard listener service running in background on Android 2.1
body: <p>I'm trying to write an app that shows a message in the infobar when the clipboard is not empty. So I need some kind of clipboard listening service. I know that Android version 3.0 SDK contains a Clipboard Listener. But I need to implement it on version 2.1.</p>
  
  <p>For example:</p>
  
  <ol>
  <li><p>My app is running on background.</p></li>
  <li><p>User has copied some text to the clipboard.</p></li>
  <li><p>My service shows that text on infobar.</p></li>
  </ol>
  
  <p>Any ideas?</p>