Kopete-facebook 0.1.2 and qjson 0.5.1 .deb packages for Kubuntu Jaunty 9.04 are available on my PPA.
To install them:

• Copy the lines below and add them to your system’s software sources. (Read about installing)
  
deb http://ppa.launchpad.net/daniele.domenichelli/ppa/ubuntu jaunty main
deb-src http://ppa.launchpad.net/daniele.domenichelli/ppa/ubuntu jaunty main
deb http://ppa.launchpad.net/daniele.domenichelli/backports/ubuntu jaunty main
deb-src http://ppa.launchpad.net/daniele.domenichelli/backports/ubuntu jaunty main

• Import public key for my PPA:
  
  sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 9D0C02D0

• Update and install package kopete-facebook
  
sudo apt-get update
sudo apt-get install kopete-facebook


EDIT:
kopete-facebook is now in my backports ppa (see https://blogs.fsfe.org/drdanz/?p=70)