Official Ubuntu packages Edit
Freeciv packages are provided by Ubuntu. List them with, e.g.,
aptitude search freeciv
As of Ubuntu Karmic (9.10) the freeciv and freeciv-client packages are virtual: choose either freeciv-client-gtk or freeciv-client-sdl. Client packages install the server, et al, but do not install sound. The virtual sound package, freeciv-sound, currently installs the only available physical sound package, freeciv-sound-standard.
Installation examples Edit
To install the GTK client and sound, do (e.g.)
sudo apt-get install freeciv-client-gtk freeciv-sound