Automator is a cool little app that comes with OS X that makes it much, much easier to programmatically control the various applications on your computer (all the good ones anyway). It’s all done by dragging and dropping actions into a workflow – the output of one leads to the input of the next. In Leopard, Automator got a big upgrade so it can now handle loops and variables but most of the time you don’t need them.

One handy feature that’s not obvious though is that if you save your workflow as an application (File->Save then select Application instead of Workflow) you can drag and drop files onto it and they become the input to the first action. So to create a droplet that resizes images to 50%, just drop the resize image action into a workflow and save it as an application. Any image you drop onto it will be resized to 50% (overwriting the original – you might want to take Automator’s advice and add a copy task too).

This proves particularly useful when combined with the wireless printer/scanner I have since it can automatically open the scanned file in any application you specify. I now have a “Process Receipts” workflow that copies the file to my Ephox Receipts folder, adds the date to the filename, resizes it to 25% (seems to be the right balance of file size vs readability) and opens a new email in Entourage with the file attached and template text, ready for me to send off to the magical fairies that know what to do with that stuff (we call them Irene, Therese and Michelle). In the time I saved, I wrote this blog post…