installation instructions for Ubuntu on website
the installation instructions for Ubuntu on the website are incomplete, it doesn't say how to install on hoary and that's the version everyone's using right now (and the not so technically inclined will continue to do so for some time to come).
To install Gajim on Ubuntu hoary (the current stable):
$ wget https://unstable.nl/ubuntu/gajim_0.8.2-1_i386.deb $ dpkg -i gajim_0.8.2-1_i386.deb
Installing the Debian unstable package on Hoary doesn't work because of dependency problems. I was able to make this Ubuntu package without modifying the debian source package though.