The latest stable release of Konversation at the time of Kubuntu's release is available in Kubuntu's regular package archive, just
sudo apt-get install konversation or use the KPackageKit package manager to install it.
For stable releases occurring after Kubuntu has been released, they are usually made available through the official Ubuntu backports. To enable this:
Development versions of Konversation are usually uploaded to the development version of Kubuntu during the course of the development cycle.