I don't currently use a gateway-PC at home myself, as to me this seems a waste of energy: this PC has to be on 24*7 to be functional, so even uses energy while no-one of the family is using a client-PC. But i was interested in this Untangle-initiative, as it tries to protect you from spam, virusses, malware, phishing and more ... and is open-source. Maybe one day i will give it a try, or maybe it is possible to install it on another device that is on 24*7 anyway (router, media-box etc).