to run geodjango in ubuntu (10.04 tested)

geodjango: ubuntu: postgresql 9 - postgis 1.5

sudo apt-get update

sudo apt-get install python-software-properties

sudo add-apt-repository ppa:pitti/postgresql

sudo add-apt-repository ppa:ubuntugis/ubuntugis-unstable

sudo apt-get update

sudo apt-get install -y postgresql-9.0 postgresql-server-dev-9.0 postgresql-contrib-9.0 proj libgeos-3.2.2 libgeos-c1 libgeos-dev libgdal1-1.7.0 libgdal1-dev build-essential libxml2 libxml2-dev checkinstall

psql --version

wget http://postgis.refractions.net/download/postgis-1.5.2.tar.gz
tar zxvf postgis-1.5.2.tar.gz && cd postgis-1.5.2/
sudo ./configure && sudo make && sudo checkinstall --pkgname postgis-1.5.2 --pkgversion 1.5.2-src --default

sudo su - postgres
POSTGIS_SQL_PATH=`pg_config --sharedir`/contrib/postgis-1.5
createdb -E UTF8 template_postgis
createlang -d template_postgis plpgsql
psql -d postgres -c "UPDATE pg_database SET datistemplate='true' WHERE datname='template_postgis';"
psql -d template_postgis -f $POSTGIS_SQL_PATH/postgis.sql
psql -d template_postgis -f $POSTGIS_SQL_PATH/spatial_ref_sys.sql
psql -d template_postgis -c "GRANT ALL ON geometry_columns TO PUBLIC;"
psql -d template_postgis -c "GRANT ALL ON geography_columns TO PUBLIC;"
psql -d template_postgis -c "GRANT ALL ON spatial_ref_sys TO PUBLIC;"

createdb -T template_postgis demo_geo_database

createuser --createdb -P <user de ubuntu>

latest version

apt-get install python-software-properties

add-apt-repository ppa:ubuntugis/ubuntugis-unstable
add-apt-repository ppa:pitti/postgresql
add-apt-repository ppa:pi-deb/gis

apt-get update

apt-get install postgresql-9.0-postgis
A basic template database can be created with the following commands:

sudo su - postgres

createdb template_postgis
psql -q -d template_postgis -f /usr/share/postgresql/9.0/contrib/postgis-1.5/postgis.sql
psql -q -d template_postgis -f /usr/share/postgresql/9.0/contrib/postgis-1.5/spatial_ref_sys.sql
psql -q -d template_postgis -f /usr/share/postgresql/9.0/contrib/postgis_comments.sql
cat <<EOS | psql -d template_postgis
UPDATE pg_database SET datistemplate = TRUE WHERE datname = 'template_postgis';
REVOKE ALL ON SCHEMA public FROM public;
GRANT USAGE ON SCHEMA public TO public;
GRANT ALL ON SCHEMA public TO postgres;
GRANT SELECT, UPDATE, INSERT, DELETE
  ON TABLE public.geometry_columns TO PUBLIC;
GRANT SELECT, UPDATE, INSERT, DELETE
  ON TABLE public.spatial_ref_sys TO PUBLIC;
EOS
To test database creation you can do the following:

createdb --template template_postgis test_gis
psql -d test_gis -c "select postgis_lib_version();"