install postgis（2.0） on ubuntu（12.04）

sudo apt-add-repository ppa:sharpie/for-science # To get GEOS 3.3.2
sudo apt-add-repository ppa:sharpie/postgis-nightly
sudo apt-get update
sudo apt-get install postgresql-9.1-postgis

sudo su postgres
createdb postgis_template
psql -d postgis_template -f /usr/share/postgresql/9.1/contrib/postgis-2.0/lwpostgis.sql
psql -d postgis_template -f /usr/share/postgresql/9.1/contrib/postgis-2.0/spatial_ref_sys.sql

psql
ALTER USER postgres WITH PASSWORD '';