The Zend Developer Zone has posted a new tutorial (from Matthew Weier O'Phinney) about a handy feature of the Zend Framework's view layer - view helpers that can be added in and reused across an application to do some pretty cool stuff.
A View Helper is simply a class that follows particular naming conventions, When attached to a view object, you can call the helper as if it were a method of the view object itself. The View object retains helper instances, which means that they retain states between calls.
View helpers can be use to do things like manipulate view data for more complex operations and carrying over data between two views, limiting the number of fetches that have to be done. He shows how to create a simple helper - My_Helper_FooBar - that just appends "fooBar " to whatever's passed in. He also talks about some of the default view helpers (like form fields), partials, the doctype() helper, capturing/caching content to be used later and the use of placeholders.