Earlier today I was trying to add some php_value's to my .htaccess file to automatically append ( php_value auto_prepend_file ) some files to my PHP scripts, unfortunately it turns out my host has not allowed this feature, but it set me off on a tangent reading all about the humble .htaccess file.
I've rarely used this file. On odd occasions to implement secure directories but other than that I've not really looked at it, but after reading some of these articles it's a pretty powerful file. I was intrigued by the abililty to ban "hot linking", bad bots and site rippers simply using this file. As a result I've now enabled some of these features to cut down bandwidth on some websites I run, I'd seriously recommending some time to research this humble file.
Further Reading
http://httpd.apache.org/docs/1.3/configuring.html
http://httpd.apache.org/docs/1.3/howto/htaccess.html
http://apache-server.com/tutorials/ATusing-htaccess.html
"How To"
http://javascriptkit.com/howto/htaccess.shtml
Changing Config. files with php
http://uk.php.net/configuration.changes