Audio tagger that "listens" to the music instead of reading the filename?

If you use iTunes, try a utility called TuneUp. It does what you asked for, an also retrieves cover art.

Musicbrainz Picard I recall does that. Haven’t used it in several years now, it may be called something different now.

“On top of using available information, like file names, to suggest changes to your tags, Picard also uses AcousticFingerprints of songs to semi-automatically identify songs in your collection.”

Source:
http://lifehacker.com/5266613/six-best-mp3-tagging-tools

Here’s a link to the TuneUp download free trial. http://www.tuneupmedia.com/download

The last part of the question should read:

Where can I dispose of my roommates dead body?

I usually keep the bodies of my victims in my basement, so that I can continue to visit them.

Winamp has this baked into it.