I've been working on a UDP Chat Client for a few weeks, it basically enables computer on the same LAN (Local Area Network) to be able to chat together using the UDP protocol.
I know this might sound useless but it could be great in a Huge LAN like the one in the GUC, students in different rooms in the University can chat together (COOL ?), and I also wanted to learn about UDP.

How to use it ? when you lunch the exe you'll see a dialog, type in the Computer Name you want to chat with or it's IP Address, if you don't know it try the "Find PCs" option, then type in any port number (like 9090), then do the same on the target PC and remember to use the SAME PORT ! after that press "Connect NOW" and you'll see the simple chat window.

You can also try Chatting with yourself by typing "localhost" as the Computer Name.
This app MIGHT work with computers NOT on the same LAN but I dunno how and never tried it before.
You'll need the dotNet Framework 2.0 (comes with Win Vista) to run this app.