But, your global vars, to be variables of this class ... !! looool
Only if you have more than 1 class, when use these vars ... !!
Our preocupation to be our scripts to do fast and robust ... !! loool
The most simple way, is to execute script and count how many time it executes ... !! loooooool
We have a lot of tools for this measure, like zend studio profilling ... !! loool