Here is a function that's help me find what chr(number) outputs what character quicker than typing out 256 echo tags.

<?php
 function listChr(){
  for ($i = 0; $i < 256; ++$i) {
  static $genNum;
  $genNum++;
  echo "chr($genNum) will output '";
  echo (chr($genNum));
  echo "'< br>\n";
  }
}
listChr();
?>

Another helpful chr is #9, being a tab.  Quite using when making error logs.

 $tab = (chr(9));
 echo "<pre>error{$tab}date{$tab}time</pre>";

 -- HappyEvil