Here is nice php script that will search for available 3 character domain names

PHP Code:
<?php
///////////////////////////////////////////////////////////////////////////////
//
// Scans for .COM, NET, ORG, INFO, BIZ, US domains
//
///////////////////////////////////////////////////////////////////////////////
// This is the number of domains the script will stop at.
$i 100;function checkdomain($xserver$xdomain) {
$sock fsockopen($xserver,43) or die("Error Connecting To Whois Server");
fputs($sock,"$xdomain\r\n");
while(!
feof($sock))
$result .= fgets($sock,128);
fclose($sock);
if(
eregi("No match",$result)||eregi("NOT FOUND",$result))
return 
true;
else
return 
false;
}

$chars = array("a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p",
"q","r","s","t","u","v","w","x","y","z","0","1","2","3","4","5","6","7","8","9");

echo 
"<style>.domains {font-size: 10px;font-family:Tahoma;color:black;font-weight:bold;}</style>
<div class=\"domains\"><u>Scanned and found</u> "
.$i." <u>domains</u>:<br />\n";

while(
$i 0){

$current $chars[rand(0,35)].$chars[rand(0,35)].$chars[rand(0,35)];

if(
checkdomain("whois.nsiregistry.net",$current.".com")) {
echo 
$current.".COM\n<br />"$i–; }

if(
checkdomain("whois.nsiregistry.net",$current.".net")) {
echo 
$current.".NET\n<br />"$i–; }

if(
checkdomain("whois.pir.org",$current.".org")) {
echo 
$current.".ORG\n<br />"$i–; }

if(
checkdomain("whois.afilias.net",$current.".info")) {
echo 
$current.".INFO\n<br />"$i–; }

if(
checkdomain("whois.biz",$current.".biz")) {
echo 
$current.".BIZ\n<br />"$i–; }

if(
checkdomain("whois.nic.us",$current.".us")) {
echo 
$current.".US\n<br />"$i–; }
ob_flush();
flush();
}

echo 
"</div>";
?>