I've been wondering about network-based bookmarks. Not a website where you can bookmark stuff, but a network service that will publish your bookmarks to a client, like a browser, for quick access, and url-completion (like in your history). This would kind of be like an LDAP-based address book.
One way to accomplish something like this would be through the use of Bonjour, because some browsers have a listener for it, like Camino. Doing a little digging I found this:
DNS Service Discovery (DNS-SD)
DNS Service Discovery appears to possibly be what I'm looking for. However, I'll just sit on the idea for awhile, because I'm wondering if it wouldn't be complete without a way to archive and publish (or hide) your history as well.