Firefox Extension for self-signed/expired certs (Score 1)

Check out: http://www.cs.cmu.edu/~perspectives/ This is a research project at Carnegie Mellon. The idea is that "network notary" servers scattered across the Internet uses network probing to build a history of keys uses by a server. When a client receives a self-signed/expired cert, it can compare with the certs seen by the network notaries and see if that key is value, or the result of a man-in-the-middle attack.