F-Secure has developed a security product designed to integrate with Facebook and check for malicious links.

F-Secure ShareSafe Beta – Security Application for Facebook
http://www.f-secure.com/weblog/archives/00002243.html

QUOTE: Security applications and Facebook tend to mix together like oil and water.  Therefore, when attempting to develop a security application for Facebook… it had better not be boring. And that brings us to our new beta: F-Secure ShareSafe. The development team behind ShareSafe aims to build an entertaining Facebook app, with security benefits tagging along for the ride.