The good folks at KDE have devised an apparently simple way to allow GTK apps
to integrate into KDE to the point of using KDE file and print dialogs.
There's some documentation on this at
and the sources are available from
or more generally
and then nav through the latest KDE dir to the utils dir.
Combined with the QT-GTK theme for GTK apps there's a good possibility of
getting Firefox to resemble and work like a native KDE app.
I must admit that I don't hold out much hope on this given the disposal of the
earlier QT port for Mozilla but this isn't nearly as ambitious.
I don't see why this request is particular to Firefox -- could not the same
technology be used to integrate Mozilla into KDE as well? If so, perhaps the
original poster could change the "Product" field to "Core".