Mozilla seems to refuse to provide a decent KDE integration in Firefox, so, at least, there are some good souls who created kgtk and others who packaged it for kubuntu.
To install it, open a terminal and execute the following:
- Add the repository source, running kdesudo kate /etc/apt/sources.list and paste the following in the end of the file:
deb http://ppa.launchpad.net/kgtk/ppa/ubuntu jaunty main
- Add the repository keys: sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 9F8C7211
- Update the packages: sudo apt-get update
- Install the desired package: sudo apt-get install kubuntu-kgtk
- Restart firefox
- Be happy!
The kubuntu-kgtk package installs configurations for several other applications than firefox, like Gimp, Kino, etc. I've seen a glitch with GIMP where after selecting a file to save, the dialog for the specific format parameters (like jpeg, gif or png) do not have focus when appear, so you'll have to find it in the taskbar.
Another thing to watch is that only the .desktop laucher files are modified. So, if you have firefox in the favorites, you'll have to remove it and add again, since the favorite (or panel launcher) is a copy, not a link of the original launcher.