Easy way to rename files sequentially?

[cothrige]

I sometimes have a list of files which I would like to rename both in a
group and in sequence.  In the past, for very long lists of files with a
number in the name, e.g. "some random audio file ep 01 of 200.mp3", I
would use thunar as it will very easily and automatically add a
sequential number to the front of the names, resulting in 01-xxx.mp3 and
so on.  Of course, there are many reasons I would rather not have to use
thunar, and would prefer to be able to do it from within emacs.  I have
managed to do this a few times using wdired and a keyboard macro, and
this really isn't too bad.  But it seems there must be a better way to
rename a list of files and sequentially number them.  Is there some
relatively easy way to add such a numerical prefix to a list of files?

Patrick