There is an app that comes standard with Mac OS X – in fact, it’s been there for many of the operating system’s iterations – that is, for me, an unsung hero of the power of the Macintosh.
It’s called Automator. According to Apple,
Automator is your personal automation assistant, making it easy for you to do more, and with less hassle. With Automator, you use a simple drag-and-drop process to create and run “automation recipes” that perform simple or complex tasks for you, when and where you need them. (source: apple’s mac 101)
Mac users can access Automator by typing “Automator” into the Spotlight search (top right in the menu bar).
Why I love Automator
As webmaster for SKKSA, I need to prepare hundreds of photos to go online in a single update of our website’s gallery. When a photo is taken by our photographers, the hi-res file size is over a megabyte, making it unwieldy for use on our website (we try to optimize it for as many users with varying Internet connections and technologies). Furthermore, I need photos to have meaningful file names so that I can easily manage them once they’re on our server.
Enter Automator: I design workflows in Automator to take a bunch of photos I’ve dropped into it, and re-size them by a certain percentage factor. Then I arrange for Automator to rename the files sequentially, appending a number to the prefix, and then the named description (usually the name of the event). Clicking “Run workflow” sends this wonderful robot into action, and it diligently executes the workflow I designed.
This process saves me at least two hours’ work.
But Automator goes beyond simple file tasks. You can use it to design PowerPoint and Keynote presentations, rotate images, even execute system tasks such as operating the iSight camera within an app like iPhoto.
Automator is just another reason why I’m in love with the Macintosh, and why I can’t imagine life without my beloved MacBook Pro.
Life in Pixels 
So true. I’ve actually only really begun scratching the surface in regards to Automator’s functions, and I’ve found it so so useful. I think Apple should further integrate Automator like functions into OS X – it’s an ingenious, however underused tool which has never received proper recognition from iFans.
Automator is really cool… It is quite integrated into OS X already; check out the Mac 101 article by Apple (http://support.apple.com/kb/HT2488) that walks through creating a service in the iPhoto app to trigger iSight. Quite neat.