Easy solutions and ideas found after long googling or hard coding

Using iptables to block ips that spam or attack your server

Check Configuring iptables on CentOS post.

Why should you do that while APF or CSF can do it automatically?
Because APF/CSF could block an important bot testing your server to add to search index. So reviewing every ip would be a daily task!
Ok, so how?
using RHEL4, centos4

get an array containing random integers between $min and $max integers

Trying to pick up random keys from an array but don’t want any duplicates?
try this

Using Google AJAX API to copy google results in array

This is some way you can get Google results as a JavaScript array that you can display on any page, you first need to get your Google API Key then try this code…

Get average server load

This function should work on Unix as on windows

Allow bots / spiders / crawlers into your private vbulletin forums

There are some very complicated hacks to add but this one line script to do it.
This should be applied to VB 3.5.4
add these lines to the end of your init.php file located in forumroot\includes\init.php