This little perl script (Ren) renames m'mp3s. Into some format which isn't too tricky for me to remember, so I don't need to look in the directory. It's probably unoptimised, and the order of regexps seemed to be important, or so I recall. I daren't touch it, because... well, it works.
Have it, if you like. But if it gives your files all rude/untypable names, don't come crying to me. Unless you want me to laugh at you.