Anyone know how to block yahoo's new option of messenger being in the
yahoo mail beta? I know we could just block access to yahoo mail, but
that hasn't been a real problem at this point (according to our logs
anyway) but now that messenger has been added there, it certainly could
become a problem.

Have already blocked webmessenger for yahoo and msn, are there others
now? we have the other general blocks for the clients (port
redirections etc)

Thank you,