title: Debian send ip address on startup (sheevaplug)
body: <p>I'm having a sheevaplug with debian (default) installed on it.</p>
  
  <p>I would like to receive a mail with the ip-address of the sheevaplug, everytime it is restarted, AND everytime the ip address changes.</p>
  
  <p>I have no idea how to do this...</p>
  
  <p>I realize I'm asking multiple things at once, so part of the solution is also ok:</p>
  
  <ul>
  <li>how to write something that runs on startup?</li>
  <li>how to send a mail?</li>
  <li>how to detect a change in ip address?</li>
  <li>how to retrieve the correct ip address? (ifconfig gives a lot of information I don't need)</li>
  </ul>
  
  <p>Thanks!</p>