Expires August 31, $75 off the "normal" price of $200. For details and purchase, see the PHP certification section of the Zend.com site.
Zend are celebrating the 600th PHP certified engineer, so they've decided on this discount. Which is nice. $200 has always seemed a bit more than an open-source developer is willing to pay for an exam, so a discount is always appreciated 😉 (I, myself, profited from another discount, offered at a local PHP conference earlier this year.)