Being still rather new to the Apple Mac, I googled the web for instructions on how to install PostgreSQL 9.1 on my Macbook Pro.
After a couple of hours, I almost gave up because all I could find were very complex installation instructions. I downloaded the package from http://www.enterprisedb.com/products-services-training/pgdownload.
Brilliant how easy this went. No instructions needed whatsoever, just click and go! Job well done.
Next, I downloaded the installer for PgAdmin here: http://www.postgresql.org/ftp/pgadmin3/release/v1.14.1/osx/
And voila. All is working :-)
One challenge left, how to make my old laptop (which is running as a VM on my Macbook) connect to the server I just created...