Meracl MP3 Renamer is simple FREE program which lets you rename the downloaded mp3 files from internet to logical files name which includes the song title, artist name etc which will help you recognize the song at the time of playing in mp3 player.
Let’s understand this with an example, lets say you have a mp3 song with the file name as Track04.mp3 this little mp3 renaming lets you rename it to something like Will Smith – M I B.mp3
     
It uses the ID3 tag which remains intact in any mp3 and uses the information to rename the cryptic looking MP3 files into something more logical which you can understand better.

I tested this software on some of the songs I downloaded from internet of a bollywood movie called Delhi 6
Here is the snapshot of the mp3 song files of the movie looks like before the reame by meracl mp3 renamer ( you can click the image below to enlarge ).