I looked at the price of Zend Certification at the end of last year, at the time it would have cost more for me to actually stay near the training college than it would to do the exam, so I think I'll wait untill it's a bit more widespread, when local educational institutions start to administer the training, or I live nearer to one of the places that do it currently, it's most definately on my list.
I don't really think it will teach me anything ( probably remind me of loads though ), it's just it's the only "Qualification" that there is really for php so it's a must have at some point, but I'm not gonna put myself out to do it, not really put myself out so much as spend more than I'll make from getting it .....
PHP Designer do a free IDE, and it's very good for beginners and professionals that are cheap.
The generalization that commercial software is always higher quality than opensource or free software is rubbish, there is plenty of free or opensource alternatives that kick the --- off thier commercial equivalents, php being only ONE of them, apache being another, vmlinuz being another .... the list goes on.
Probably the best free one is PHP designer, and then when you're earning some money out of your skills you can use the paid one with all it's extra features without having to learn a new IDE.