One of the things you can’t do in the Mac OS Finder is rename groups of files at once. Automator makes batch renaming a piece of cake: simply use the Rename Finder Items action and then save the resulting workflow as a drag-and-drop savvy standalone application.
The Rename Finder Items action has lots of options, so it’s worth exploring. The pull-down menu sets the way the file will be renamed. The Add Date or Time option appends some time-dependant phrase to the item’s name. This would obviously be useful for things that need to be time-stamped in some way, such as data backups, news articles, or software development projects. The Add Text option pastes some words onto the start or end of the file name. An example of where you might use this is to add a file extension (such as ".zip" or ".txt") to a bunch of files to make them easier to identify and share between computing platforms.
The Change Case option is pretty self-explanatory—it lets you switch between upper-, lower-, and title case formats. This is particularly useful where files need to be made available online because URLs are often case sensitive. The Make Sequential option is very useful for creating batches of items in numerical order. If you have a bunch of photographs to be placed in a gallery on a web site, you could use this option to rename them from their generic digital camera names to something more useful, such as "sales_trip01.jpg", "sales_trip02.jpg", "sales_trip03.jpg", and so on. Finally, the Replace Text option is great for processes such as replacing blank spaces in file names with underscore characters—a useful trick when prepping graphics for use on web sites.
Figure 7 Use Rename Finder Items to create a batch file renaming workflow.