Dither is a small app that is the result of my experimentation with Python,
GTK+, mutagen and probably a few other technologies. It's probably not useful
to you. If for some strange reason, you want to run it, just check out the
source and run dither.py. And install mutagen (python-mutagen on Ubuntu) if you
don't already have it. 

You can use the file chooser button to select a file (or drag and drop a file, 
or pass it a single file as an argument) and if it's a music file with tags 
that mutagen understands, it'll display the raw tags (except for coverart tags, 
which can be flippin' huge). It's basically a GTK+ version of mutagen-inspect.

Told you it wasn't useful.