File List is another Mac app that I couldn’t live without. When I put together music and sound effects collections I receive huge amounts of data from composers all of the world. They send their files with all kinds of bizarre naming conventions and I used to go through file by file and change every single title by hand.
It finally got so out of hand that I did a quick search and found File List (Name Mangler now?) and have been using almost everyday since I downloaded it.
File List batch renames files on your Mac according to criteria you set up. Rename files using sequential numbers, prefixes, or suffixes, or change to upper or lower case. File List supports advanced file naming specs that let you use conditional statements too.
You can download it here
http://www.manytricks.com/namemangler/
and start renaming files.