Update as mentioned by Chaudhry Waqas in comments it might be sufficient to just add define('FS_METHOD', 'direct'); to wp-config.php, so please try this first as it’s safer not to change access rights if not necessary
WARNING: only do this on your local computer, it’s a huge security risk on a public installation!
I haven’t tried it but as mentioned by @misterfancypants comment, changing those settings only for
wp-content/plugins/should be sufficient
updated to incorporate this info
This one worked for me
$ cd /Users/<username>/Sites
# (wordpress = name of the directory, change as needed)
$ sudo chown -R :_www wordpress
$ sudo chmod -R g+w wordpress
and then add following in wp-config.php
define('FS_METHOD', 'direct');
found on http://soderlind.no/running-wordpress-locally-on-mac-os-x-lion/#crayon-533a956214a8e343167867
Cheers Can