I Have to take issue with one of the services Chad discusses. The Universal Plug and Play is not the ubiquitous Plug and Pray service used for hardware installation. Upnp is used to identify networked devices, usually routers etc, so that a common set of protocols can be configured (by UPnP) so that the end user doesn't need to dirty their hands with router configs and firewall settings.
True, UPnP is dangerous if left to its own devices, or worse left to a Worm or trojan to configure. I don't take issue with disabling the service, just the reason given.