Good news is that Mac OS X 10.7 Lion will no longer have a server version. Instead all the server tools will be included in the typical version of Mac OS X.
But strangely, despite Apple’s support for WebDAV across Mac OS X and iOS devices, it is not possible to easily turn your Mac into a WebDAV server. For example, the iWorks app on iPad can export files to WebDAV server. But there is no easy way to export it directly to your Mac, because even though in “sharing” settings you can share your files by AFP, FTP or Samba(Windows), you cannot set up WebDAV share.
So I found this tutorial that have easy to follow steps to turn your Mac into a WebDAV server. Of course if you do not have a static IP address or domain name, you will be in more trouble but I am not going to cover that aspect. I have confirmed that it works with iOS iWork apps. Unfortunately it seems the folder has to be in /Library/WebServer/WenDAV. Luckily you can always hard link it to your working folder somewhere else.