Version: (using KDE 4.3.0) OS: Linux Installed from: Gentoo Packages There should be an option to select an user where you get notified when he or she changes its online status e.g. from offline to online. This is very helpful if you wait for an special user to come online or something.
In the current version of Kopete there is such functionality - in a contact properties you can change its own notifications. The problem is there is only one related notification - when the contact goes online, there is no notification for other changes.
Dear user, unfortunately Kopete is no longer maintained. Please migrate to another solution, e.g. for Jabber a possibility is Kaidan, for Matrix a candidate is NeoChat.