Rather than sit down and retype the names on each one of the files, Renamer lets you set up a simple renaming scheme that can be applied to a range of files. Through a very straightforward interface (see below), you can display all of the files in a folder or nested set of folders. Once the files are displayed on the left side of the interface, you can determine what kind of presets to apply to the file names.
One thing I like about the new Renamer is that it's easy to chain presets. For example, let's say that I want to rename all of those IMG_0729.jpg file names to something more indicative of what the files actually contain. I can start by eliminating all of the text prior to the file extension (.jpg), and then replace it with the text "iPhone " and a sequence of numbers. These are two different presets, which can be chained together into one action.
When a chain of renaming presets has been created, it can then be saved. A new feature of Renamer is that it allows you to do renaming not only from the application, but also from the Finder. There's a new system menu that you can use to apply your presets from the finder.
I felt it was much more informative to use the application for renaming. I can see exactly what the new file names are going to look like before applying my renaming presets, and if I do something wrong, there's an undo feature that will set all of the file names back to their original status.
If there's one complaint I have about Renamer 4, it's that it doesn't have a built-in help file. I was able to figure out most of the application's capabilities just by trial and error, but since I'm one of those odd people who actually does read manuals and help files when something's not clear to me, it would have helped to have had some clear instructions on how to use the app.
Renamer is great for photographers, writers, and anyone else who needs to make sense out of a large number of files with indecipherable names. It works smoothly with Mac OS X 10.6.1 Snow Leopard, and does what it's supposed to do in an efficient manner. What else could any Mac user hope for in an application?