unable to upload image locally

I followed this tutorial on setting up a local web development setup without mamp. Now my problem is when I go to upload a image in WordPress I get the following error:

“Screen Shot 2013-01-05 at 10.51.42 PM.png” has failed to upload due to an error:
Unable to create directory wp-content/uploads/2013/01. Is its parent directory writable by the server?

It seems like it might be some sort of permissions error, but I am not sure exactly what to change.

You need to change the file permissions on your wp-content folder (and containing folders) to 755. On your setup you can do this with:

find . -type d -exec sudo chmod 755 {} \;

Please note that using chmod -R 755 will mark both directories and files as 755.