I found this program to send popup messages to other puters on your network... Works great without a stitch of configuration....
Does anyone know of another decent popup network messenger????
http://www.ariolic.com/ntpager/index.html
"NTPager it is useful network messenger for Windows NT and Windows 2000 systems. It allows you to exchange messages with one user or several users of your network, using simple and handy interface. The list of network users divided by workgroups or domains, so to send a message to anyone simply select the computer from the list, type in your message and press "Send" button. Also possibility to input the user's computer name by hands and other features are available.
Ariolic NTPager is compatible with Messenger service on Windows NT/Windows 2000 systems or with programs like WinPopup on Windows 9x/Windows ME."