On 9 sep 2001 1:46:40 GMT:
136 Days 04:05:12 Left
1.000.000.000 seconds will be counted since the UNIX Epoch ( 1 Jan 1970 00:00:00 )

Link to this counter, it's easy:
add the following code to your page:

 <a href="http://www.prout.be/time.php">
 <img src="http://www.prout.be/img.php" alt="1.000.000.000 Counter"></a>