Note that with PostgreSQL 9.0 (and probably newer) on Mac OS 10.6.8 (and probably older), in order to prevent the PostgreSQL server from auto-starting, you have to:

1. Go to?/Library/LaunchDaemons/

2. Open?com.edb.launchd.postgresql-9.0.plist?in an editor as?root?(replace?9.0?with your correct version number), e.g.?sudo vim com.edb.launchd.postgresql-9.0.plist.

3. Locate the line?<key>RunAtLoad</key>

4. Change the next line from?<true/>?to?<false/>

5. Save and exit.