I had good luck with Bulk Rename when I was on windows: http://www.bulkrenameutility.co.uk/Main_Intro.php

F2 

or maybe....my fav http://www.fauland.com/af5.htm

DIY, perl.

http://www.georgedillon.com/freeware/therename.shtml

THERename. I found this little freeware app while modding Space Empires IV (it tides me over between Stardock releases), due to my need for mass renaming.

It's quite easy to use and works like a charm, and it's easy to remember what it's called if you ever lose track of it on your OS (just search "rename").

If you are renaming Images, Adobe Bridge http://www.adobe.com/products/creativesuite/bridge/bridgehome/

Get yourself a book and learn how to use the Lego bricks of the command line. It'll give you everything that all those thousands utilities out there can achieve and more. Wether you want you a file rename, or extract data from an MP3, JPG or any other file content, there exists a Lego brick that can do it, while those utilities always have a fixed functionality. I'm sure the rename operation you desire can be achieved by the entering a well thought out command line on a Bash shell.

New tool pretty easy to use :

jRename Try it

I noticed it and thought of the exact same thing said in reply #6.

Good thing the OP didnt ask about colonoscopy's then!!!!