The kbtserialchat tool is a very simple chat client&server. Its primary purpose is for debugging and to serve as an example on how to write a bluetooth server that is managed by kbluetoothd and how to write a client that can be started with the SDP tdeioslave. kbtserialchat implements the Serial Port protocol, so when you start it, it will show you all devices which provide the Serial Port profile. This will include other computers where the KDE Bluetooth Framework is installed, but also phones which support this profile. When you are connecting to another kbtserialchat server, then kbtserialchat will pop up on the other system and you can happily send each other stupid text messages. You can also connect to the serial port of Bluetooth phones and send arbitrary AT-commands. To dial a number for instance, type ATD<number>;. While it may not make much sense to connect kbtserialchat to a serial port of a device that uses it to exchange binary data, you can use it not only to connect to serial port services, but to every service that's based on Rfcomm, like the handsfree or headset profile. Since these services are not listed in the dialog on startup, you can use the following trick: Browse the services of a device with tdeio_sdp (using a sdp:/-URL). Then instead of simply clicking on the service, right-click on it and then select Open with.... Enter kbtserialchat in the dialog, press enter - and you're connected.