In host information page - show the contacts associated with the host ( helpful in large companies where the NOC is not always aware whom is the person responsible for a specific host )
Using the "notes_url" for this and pointing to a wiki is a very helpful thing. You can keep your info in the wiki, and just give a default notes_url to every host and service. Embed the host and service names in the url, and even if the wiki page doesn't yet exist, then the user can create it (like wikipedia does).
Of course this doesn't survive upgrades or changes of hostname or service name very well...