I installed PostgreSQL using Homebrew on Lion. It starts okay but wouldn\'t shutdown. I tried:
$ #started with $ pg_ctl -D /usr/local/var/postgres -l /usr/lo
If you used Homebrew to install postgresql, then as Shevauns comment on Greg's answer indicates, the correct procedure is
launchctl unload -w ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist rm ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist