Just a note - if you get larger than normal CPU usage when using Kopete and Lancelot at the same time in KDE 4.3, visit the BUG:196809

This should be fixed in 4.3.1. In the meanwhile you can disable the Kopete integration by doing the following:

open lancelotrc file (~/.kde/share/config/lancelotrc) with your favourite text editor and add the following line to the [Main] section