Thanks! Will try it...
(PS: split this off into seperate topic..)
[EDIT]
for the record : how another script does it... for auroraGPT
[code=php]
< ?php
///////////////////////////////////////////////////////////////////
// AuroraGPT BotScout mod (basic version) for AuroraGpt 4-mrV3 //
// This mod assembled by aussiebob - rod@qifn.net - 19 Aug 2010 //
// As used on http://www.buxbunny.com - AuroraGpt 4-mrV3 //
///////////////////////////////////////////////////////////////////
// This mod will verify all new signups against external databases of
// known scammers, spammers, bots, and general pains in the ass!
// HOW IT WORKS - when the bot or registerant clicks the button the
// email and IP address are checked against the http://botscout.com
// database of known bots. If a record is found then the signup simply
// fails and the details are written to your admin site log.
// If it's a genuine signup, then the registeration goes through as normal.
// We recommend you check out the http://botscout.com site, (BTW: we are NOT
// affilated with BotScout, we just use the handy free service provided)
// NOTE: We intentionally do NOT check by username as they are too generic
// ie: a genuine signup with username holly would be rejected as a bot
// DISCLAIMER: We cannot be held accountable for any losses due to the
// misuse of this script nor any incorrect data returned from Botscout.
// Your daily signup numbers will drop as bots are detected!
// INSTRUCTIONS:
// 1- Edit the CONFIGURATION section of this file.
// 2- Place this file (botscout.php) in your members directory.
// 3- Edit the file members/join.php
// and add this line - include('botscout.php');
// directly below line $co = lookupIp($vip); so it looks like this
// $co = lookupIp($vip);
// include('botscout.php');
// Thats all folks - enjoy
// ---- CONFIGURATION BEGIN ----
// NOTE: This is optional, but without an API KEY you can only do 20 lookups daily
// Register for a FREE API KEY at http://botscout.com/getkey.htm
// Enter your Free API KEY you received by email from http://botscout.com/
$APIKEY = 'YOUR-API-KEY';
// ---- CONFIGURATION END ----
// --------------------------------------------------------------------------
// ---- DO NOT EDIT BELOW THIS LINE UNLESS YOU KNOW WHAT YOU ARE DOING!! ----
// --------------------------------------------------------------------------
// init vars
$botdata='';
$returned_data='';
// get the registerants IP address
$XIP = $_SERVER['REMOTE_ADDR'];
// get the registerants username
$XUSER = $uUsername;
// get the registerants email
$XMAIL = urlencode($uEmail);
// Assemble the query to send to BotScout.com using the registerants email and IP addresses only
$apiquery = "http://botscout.com/test/?multi&mail=$XMAIL&ip=$XIP";
// Add your BotScout.com registered user API KEY to the query
if($APIKEY != ''){
$apiquery = "$apiquery&key=$APIKEY";
}
// Send the query to BotScout.com using either file_get_contents() or cURL
if(function_exists('file_get_contents')){
// Use file_get_contents
$returned_data = file_get_contents($apiquery);
}else{
// Use cURL
$ch = curl_init($apiquery);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
$returned_data = curl_exec($ch);
curl_close($ch);
}
// Parse returned data array values
$botdata = explode('|', $returned_data);
// Display error message should there be a problem accessing the Botscout.com database.
if(substr($returned_data, 0,1) == '!'){
// if the first character is an exclamation mark, an error has occurred
print "Verification Error: $returned_data - Please try again later.";
exit;
}
// Check if the signup email and IP appear in the returned BotScout.com data values.
if($botdata[3] > 0 || $botdata[5] > 0){
// perform IP - Country lookup
$sql= 'SELECT c.country FROM ip2nationCountries c, ip2nation i WHERE i.ip < INET_ATON("'.$XIP.'") AND c.code = i.country ORDER BY i.ip DESC LIMIT 0,1';
$temp1=mysql_query($sql);
list($countrylist) =mysql_fetch_row($temp1);
$cntry="$countrylist" ;
// insert details into site logs
$sql=$Db1->query("INSERT INTO logs SET username='".$XUSER."', log='Bot Signup Failed - $XUSER - $uEmail x $botdata[5] records - $XIP x $botdata[3] records - $cntry', dsub='".time()."'");
// Generate a fake Error number (Looks more credible)
$errorfake = round(rand(1100, 20000));
// Give credit to BotScout.com and display an error message to the bot 
print "<h3>ERROR: $errorfake</h3>
<p><a href=\"http://botscout.com\" title=\"More Info...\" >Registerant Identified as a Bot</a> - Registration Failed! - Exiting process.</p>";
// halt the signup process
exit;
}
// NOTE: We have added an extra mySQL table called users_rejected and actually add the rejects to it.
// Then we can display the info both in the admin and on the public Rejects page.
// This is an optional extra - fig it yourself - or ask for help in the EMS forum - Private
?>
[/code]
looks a lot easier yes 
