Let's face it. The Zend Framework, like most web frameworks, has set some lofty goals: high quality components, a complete system for developing web applications, and simplicity. [...] As the framework is still sub-1.0 and mainly for early adopters, there's an easy way to determine whether the Zend Framework is right for your development efforts. So who is using the Zend Framework?

He mentions Lars Strojny's application - PhpWishList (demo) that started a new page on the Zend Framework's wiki - the applications page of projects and applications using the Zend Framework.