Do you want to replace Messenger Service in Windows XP, 2003?

Messenger Service is a service in Windows that allows people to send messages to each others in a local network. But in my opion, it's so simple for people to send messages quickly and the receiver has to type command "net send [computer name] [message]" to reply the message which he has received.
I was finding a program that can do as much jobs as KLinpopup does, and finally I found it, RealPopup. It has an user-interface like KLinpopup, but I think that it is the comfortable user-interface for such these programs.
You can learn more about how it works by reading the article of matro, its author, at this address at CodeProject.