Replacement for send command in Windows Vista

I tried researching this on my own with no avail. I came across and signed up here at the TechRepublic. I did find a few posts, but the people who answered thought the question were about instant messenger, not the command prompt send command. I know it is no longer in Vista because of security issues. I am old school, and don’t use instant messenger (yet).
I am testing Vista (giving it a fair trial) and would like to send other users admin messages. I don’t like people using instant messengers at work for obvious reasons. I’m not a die hard but we are in business for a reason : ). Thanks in advance