BTW,Can you guide me about the conference in September in CA?
I wish. It should be a lot of fun, but I'm just not going to be able to take the time off ):
If you're not already, make sure you're registered by September 10 (
http://www.zendcon.com/ZendCon08/public/content/reg). Early registration was back in June, but you can still save a little bit compared to what you'd have to pay at the door.
They're hosting "tutorials", which you'd probably have no need to attend; they're pretty basic PHP lessons. The actual certification training and testing takes place during the conference itself.