What is SyncDAV?
It's a couple of classes for Cocoa which attempt to replicate the syncing behavior of DropBox, but over Apache or MobileMe WebDAV servers.
You instanticate a SDManager class and point one end of it it at a local bundle (such as a VoodooPad document), and then point the other end at a folder on a WebDAV server. It'll hopefully do the rest.
But it'll really just delete your important data. It's a work in progress.
Check out the SyncDAV example application for how it works, or the tests in the jstests folder. Note: The SyncDAV app doesn't give very good info on what's going on, so check the NSLog output. Syncing is also only manual at this point.