Here are some that I found that might be useful:
http://www.homeandlearn.co.uk/php/php15p1.html
http://www.devx.com/webdev/Article/27175
http://articles.techrepublic.com.com/51 ... 83365.html
http://www.hotscripts.com/Detailed/44283.html
http://www.hotscripts.com/PHP/Scripts_a ... more2.html
http://www.hotscripts.com/PHP/Scripts_a ... index.html
http://www.scriptsbank.com/Detailed/2632.html