I have been using networkmanager applet for managing my network for some time. Reason why I used a gnome app in my kde (trust me this is the only gnome app I use, err I guess I am forgetting pidgin and firefox :p) is that this is the only fully fledged network manager available for linux. Yes kde lacks one and it sucks.
Lacks one in the sense the knetworkmanager is not getting enough love from KDE developers it seems. Still it does not support Mobile broad band or vpn connections, though the configurations are there :p . And I guess no ones wants to remember what happened when kubuntu 8.10 shipped this one. At that point even wireless was not working properly. But things are better now. But still I went back to knetworkmanager recently. And now I am using wvdial for managing the mobile broadband, which is a Reliance connection. ( Getting free from my company :D).
I followed the instructions from here configure wvdial.
But once knetwork manager supports this I am sure I will go back to it.
