You want to show some photos of the kids to your family in a secure fashion, but do not want to rely on the cloud folks to store your data? Then running Piwigo on your home server or a VPS is a great way to do exactly that.
Update: since Owncloud 5.0 the config below didn't work anymore. A slightly more complex config is needed. See this GIST: https://gist.github.com/petarpetrovic/5163565
Old info for pre 5.0 below.
Here is how I got OwnCloud's WebDAV feature to work in Nginx.