function parseTweet($str) {
        $str = preg_replace(
            '@(https?://([-\w\.]+)+(/([\w/_\.]*(\?\S+)?(#\S+)?)?)?)@',
            '<a href="$1">$1</a>',
            $str);
        $str = str_replace('>http://', '>', $str);
        $str = str_replace('>https://', '>', $str);
        $str = preg_replace(
            '/@(\w+)/',
            '<a href="http://twitter.com/$1">@$1</a>',
            $str);
        $str = preg_replace(
            '/\s+#(\w+)/',
            ' <a href="http://search.twitter.com/search?q=%23$1">#$1</a>',
            $str);
        return $str;
    }

function daysAgo($time) {
        $now = time();
        $time_ago = $now - $time;

        $day = 60*60*24;

        $days_ago = floor($time_ago/$day);

        $result = "";

        if ($days_ago == 0) {
            $result = "Today";
        }
        else if ($days_ago == 1) {
            $result = "Yesterday";
        }
        else {
            $result = $days_ago . " days ago";
        }

        return $result;
    }