NameRanger is a very simple and easy to use application designed to offer support for batch-renaming files in a particular folder systematically.
Just open a folder where you have files to rename, configure name settings and click on the Change button.
What you see under New file names is what you get. So if you are happy with what you see, then click on the Execute button to rename file names. Pretty simple...
NOTE: NameRanger 1.0 version will remain functional until July 1, 2011. After this date, you cannot launch it. If necessary, rewind the system clock to a date before that date.