applications that rename multiple files?

anyone know of any programmes that would allow me to re-name multiple file's names? something like, naming several dozen files that has random numbers as its filename to something like something_01, something_02, something_03 and such?

You think this is insane?

( COUNT=0; for FILE in *; do mv "$FILE" `printf "something_%02d" $COUNT`; let COUNT++; done; )

Maybe it is.