For a long time people have talked about an LDAP or other network-located backend for GConf. Unfortunately writing GConf backends is painful and in some ways not really possible, for example the backend interface does not support change notifications originating from the backend. Presumably Ryan's dconf will address some of this.
In the meantime, we wanted to sync certain settings to a network server as part of the online desktop effort to optimize GNOME for the Internet. I took a simple approach, first in a hacky Python prototype and now in more productized form.
The approach: an online-prefs-sync-daemon looks for a service on the session bus called OnlinePrefsManager. This service implements a Preferences interface (get and set key-value pairs, pretty much). If an OnlinePrefsManager is found, then online-prefs-sync-daemon keeps GConf in sync with it. Otherwise, online-prefs-sync-daemon doesn't do anything.
The data model service implements OnlinePrefsManager in a way that stores settings on an Internet server. However, it would be simple to also implement an LDAP or enterprise version. Or a WebDAV version if you can figure out how to do change notification that way.
Owen says it is overengineered to make OnlinePrefsManager pluggable instead of talking to the data model directly, and he's probably right as usual, but maybe someone will write the Enterprise Edition.
online-prefs-sync-daemon uses a simple directory full of files that whitelist GConf keys to be stored online. Here is an example of a .synclist file. The idea is that apps could install these, though for now I'm just shipping one with the sync daemon. In the sync list file, a GConf key can be marked to be synced among all systems, per-machine (which means the sync is for backup purposes only), or not at all.
If you have three computers on your desk like I do, it's sort of fun to change your desktop background on all three at once (the change notification means all three update live and instantly). Something like your preferred web browser or gnome-terminal profiles might be more useful to change for all your systems at once, though...
On the downside, some of the most useful items to sync - such as browser bookmarks - aren't stored in GConf. So those will have to be dealt with separately.