If you need to resize a bunch of images on your Mac, Automator is the way to do it in one fell swoop. 9to5Mac shows off how to quickly make your own Automator service for doing just that.
While Automator might be a little intimidating for new users, it's pretty easy to get the hang of it. For this one, you'll just create a new service, use the scale images action and set it up to scale to whatever size you need.
This is handy if you're bringing in photos from a camera that need to get resized for a web site, or if you're just looking to cut down on hard drive space.