Q:

Track users with PHP and JavaScript

Have I missed any obvious things that you can log to keep track on your visitors (using PHP and JavaScript)?

Can I get computer name?
Can I get the country?
Can I get the city?
Postal code?
Any other information that can be collected from certain browsers?

PHP DOCUMENT :
<script>

<?php 
$ip = $_SERVER['REMOTE_ADDR'];
$hostaddress = gethostbyaddr($ip);?>
<?php echo "document.write('The IP-adress: ' + " . "'" . $ip . "'" . " + '<br>');";?>
<?php echo "document.write('The host address: ' + " . "'" . $hostaddress . "'" . " + '<br>');";?>

document.write('The date: ' + new Date() + '<br>');
document.write('Get the entire URL of the current page: ' + location.href + '<br>');
document.write('This document was last modified on:' + document.lastModified + '<br>'); // good to know wich version of the page they have

if (document.referrer != ''){
document.write('The referrer of this document is: ' + document.referrer + '<br>')
}
else{
document.write('The is no referrer.<br>')
}

document.write('Number of URLs in history list: ' + history.length + '<br>')

// I know it doesn't allways return the right browser info, but it gives a good clue.
document.write("Browser name: " + navigator.appName + '<br>');
document.write("Browser version info: " + navigator.appVersion + '<br>');
document.write("Platform: " + navigator.platform + '<br>');
document.write("User-agent header sent: " + navigator.userAgent + '<br>');
document.write("Language of user: " + navigator.userLanguage);

document.write("Total Height: " + screen.height + '<br>');
document.write("Total Width: " + screen.width + '<br>');

document.write("Cookie: " + document.cookie + '<br>');

</script>

A:

There are a lot of geolocation databases available. If you wish to go free there are some free databases too with less frequent updates than their paid counterparts, e.g. MaxMind GeoLite. 
For more Google for IP geolocation.

