Batch-processing files is a great way to save time. Automator scripts work will for simple jobs, but if you're trying to do something complex like remove or alter the filename of a great many files, a free tool like NameChanger could be a useful addition to your armory.
NameChanger takes on file renaming with aplomb. It'll allow you to replace parts of a file name, append or prepend characters to existing file names, as well as add dates, sequences or any other regular expression. It's a little more complex than the likes of Quick File Renamer; but once you get to grips with it, it's a rapid way to process files.
One thing that's not that obvious when you first start out, is that to get NameChanger to ignore file extensions in it's processing of your file name, you have to reach into the Options menu and tick the "Hide Extensions" box. That way you can maintain the original file extensions of the files you're processing.
Once you've got that down pat, it's just a case dragging and dropping the files you want modified onto the app. You use the drop-down box to select the type of processing you want, type in the characters or select the sequence or date string and hit "Rename." Alternatively, if you want to do it all within the program you can use the "Add," "Remove" and "Clear" buttons on the toolbar.
While it's true you can perform all these functions with Automator's file actions, NameChanger brings swift flexibility to your batch-renaming tasks. It's free, so if you're after a file renamer, it's well worth checking out.
Thanks for the suggestion Brandon.