Read about Postrgres.app a few weeks ago and I decided to give it a try for my clean install Mountain Lion, turned out it is indeed the easiest (and fastest) way to get PostgreSQL up and running on Mountain Lion.
But when I tried to run psql:
psql: could not connect to server: No such file or directory Is the server running locally and accepting connections on Unix domain socket "/var/pgsql_socket/.s.PGSQL.5432"?
You can solve this by running psql -h localhost, but I don’t want to type the host parameter for all the PostgreSQL commands. The solution is to add the following to your .bash_login :
export PATH="/Applications/Postgres.app/Contents/MacOS/bin:$PATH"
Thanks Mattt Thompson and Heroku for creating this wonderful app and I look forward to seeing it up on AppStore.