I was bored this afternoon, so I wrote something quick and dirty that "should" take care of this for you.

It requires .net 2.x or greater. Open a command line window, and run the exe... Syntax is as follows...

FileRenamer.exe -path "c:\users\oliver\music" -pattern *.mp3 -recursive -update

NOTE: when -update is specified, it will actually rename the files. i'd suggest on the first run you remove the -update and look over the list of files. if you don't want to scan/update subfolders remove the -recursive function.

-pattern is also optional, if you leave it out it will basically just do *.*

the ugly code is also in the zip file, if you have visual studio.net 2005/8 you can compile it yourself. otherwise you'd need the SDK and a command I can't remember...