Quick and dirty, but it works. Scans your minecraft's server.log file and pulls out some stats.

gistfile1.php

<?php # axiixc.com

$file = 'server.log';
$contents = file($file);

$regexp_arr = array(
  'message' => '/] <([A-Za-z0-9]+)>/',
  'login' => '/] ([A-Za-z0-9]+) \[/',
  'give' => '/] [A-Za-z0-9]+: Giving ([A-Za-z0-9]+) some/'
);

foreach ($regexp_arr as $argname => $regexp) {
  $mMatches = array();
  foreach ($contents as $line) {
    if (preg_match($regexp, $line, $matches)) {
      $mMatches[$matches[1]]++;
    }
  }

  printf("-- %s --\n", $argname);

  arsort($mMatches);
  foreach ($mMatches as $userName => $count) {
    printf("%5d\t%s\n", $count, $userName);
  }

  print("\n\n");
}