We have recently developed an additional Sametime disclaimer notfication application for our Sametime chat archiving application (IMtegrity).
The disclaimer application is a Sametime Server application that monitors inbound logins to the Sametime server. When a new login takes place, our disclaimer application notifies the person (via an IM window) with a message that their Sametime conversations may be monitored and recorded.
IMtegrity has been on the market for about 5 years and this is the first request that we have received to provide a disclaimer notification.
Overview of the product is here: http://www.instant-tech.com/Disclaimers.cfm