Launching off from this previous post on the Stubbles Blog, two more posts (from two other developers) have been posted on the same subject:

• In this new post, Frank Kleine takes things a step further and talks about the same kind of type hinting but for more types - including arrays and objects. Examples of how he'd expect things to work followed.
• The other post is from Stephan Schmidt again and varies slightly off into the world of Namespaces to be included in PHP6 along with the use of annotations.