Evert Pot has posted about a library he's creating to integrate WebDAV support with PHP and make things simpler for those needing to access the shares.

I intend to make this library as easy as possible to use, without making it a black-box-like system. Focus will not be on everything WebDAV could possibly provide, but instead on the features that are actually supported by the operating systems.

His goal is to make it as simple as making a 'File' and 'Directory' class to interface with the remote system and has two things he's deliberating on as far as features to include in the library - support for the custom properties WebDAV allows and the ability to lock files and directories.

If you'd like to check out the current progress of the library, check out its page on the Google Code site (as well as this discussion group he's set up).