function for converting unix timestamp to useful text

Hi all looking for a function that will take a unix timestamp and make a relative conversion to now. This is for comments and I was wondering if there is anything out there to convert to a timestamp like digg has, for example '3 minutes ago' or 'last month', rounding off to the nearest thing that makes sense. Anyone seen anything like this?

 

I wrote this some time ago.

function calc_date_diff($timestamp_past = false, $timestamp_future = false, $years = true, $months = true, $days = true, $hours = true, $mins = true, $secs = true)
{
	// Use current time if parameter is FALSE.
	if (!$timestamp_past)   $timestamp_past = time();
	if (!$timestamp_future) $timestamp_future = time();
	
	// Attempt to convert strings to timestamp if necessary.
	$timestamp_future = is_string($timestamp_future) ? strtotime($timestamp_future) : intval($timestamp_future);
	$timestamp_past   = is_string($timestamp_past)   ? strtotime($timestamp_past)   : intval($timestamp_past);
	
	$diff = $timestamp_future - $timestamp_past;
	$calc_times = array();
	$timeleft   = array();
	
	// Prepare array, depending on the output we want to get.
	if ($years)  $calc_times[] = array('Year',   'Years',   31104000);
	if ($months) $calc_times[] = array('Month',  'Months',  2592000);
	if ($days)   $calc_times[] = array('Day',    'Days',    86400);
	if ($hours)  $calc_times[] = array('Hour',   'Hours',   3600);
	if ($mins)   $calc_times[] = array('Minute', 'Minutes', 60);
	if ($secs)   $calc_times[] = array('Second', 'Seconds', 1);

	foreach ($calc_times AS $timedata)
	{
		list($time_sing, $time_plur, $offset) = $timedata;
		
		if ($diff >= $offset)
		{
			$left = floor($diff / $offset);
			$diff -= ($left * $offset);
			$timeleft[] = "{$left} ". ($left == 1 ? $time_sing : $time_plur);
		}
	}
	
	return $timeleft ? ($timestamp_future > $timestamp_past ? null : '-') . implode(', ', $timeleft) : 0;
}

PHP: