FixTag is a Java/Swing application that lets you edit the fields within MP3 ID3 tags.
They say a picture is worth a thousand words, so instead of blabbing on about this program, I'll show you what it looks like and let you draw your own conclusions. (And in case you are wond'ring, yes, I legally own this Pantera CD.)
Here are some MP3 files that don't have the correct name in the Artist field
Select all the files and right click to bring up the Batch menu
Enter in the value for the field (or select from a list of possible values)
Now they are all better
You can double-click a row to dive into the ID3 tag details
You can configure how you would like filenames to look for automatic renaming
You can select what ID3 tag details you want displayed in the list
