Version: (using KDE KDE 3.5.8) Installed from: Fedora RPMs OS: Linux The KDE system tray can get cluttered... not as bad as Windows yet, but it can be quite ugly. The KBluetooth icon should hide itself if there is no Bluetooth adaptor plugged into the system. When no Bluetooth adaptor is plugged in, the only menu options available are "Help" and "Quit", so it is quite useless anyway. From a usability PoV, it should probably show itself for 15 seconds before it hides, or display a passive notification with a clickable link allowing you to bring it back, or having a command line option to not auto hide, otherwise some users may complain that they loaded kbluetooth but nothing happened. (Or there may be someone who just wanted to read the "Help" pages).
Use /usr/bin/kblueplugd instead of /usr/bin/kbluetooth to start program. kblueplugd are receiving events when bluetooth device plugged/unplugged and starts/stops kbluetooth depending on number of devicces are plugged. If no bluetooth devices are present in a system, kblueplugd hides icon in a systray. Original kblueplugd written in Python/Qt4 but you can find plain C++/Qt4 implementation of kblueplugd in attachment of bug 160676 (https://bugs.kde.org/show_bug.cgi?id=160676).
kbluetooth is unmaintained. See http://bugs.kde.org/27070 This is fixed in Bluedevil, which replaced kbluetooth.