Update: Since writing this I've instead started using jQuery for my Ajax needs, you should too, or MooTools maybe. I've written a new piece demonstrating how jQuery can be used with ZF.
Widely hailed as the successor to XML in the browser, JSON aspires to be nothing more than a simple, and elegant data format for the exchange of information between the browser and server; and in doing this simple task it will usher in the next version of the World Wide Web itself.