[Skunkworks] facebook block

Hi skunkers, is there a way you can block facebook in a domain?i need to block it within a school environment. im running on server 2008 enterprise but with only one network card. my domain is a child domain to another network but i wouldnt want the rest of the network to block facebook, just my domain. there exists a proxy server within the school environment,of which i dont have access to. is there a way i can do accomplish this Herculean task using an open source solution? -- "do not look at where you fell but where you slipped" -African Proverb