Based on Gina Trapani's public domain Lifehacker Blackener script.

v0.2.5:

Metafilter user 'carsonb' tweaks CSS to prevent padding/margin from throwing off permalinks to comments on the site.

v0.2:

Metafilter user 'VoidContext' offered new CSS which looked far, far, far better than original hack.

"If" Javascript code suggested by Metafilter user 'Tuwa' allows this one script to cover the three primary domains of Metafilter.

v0.2.1:

Now with magical Projects and Music goodness.

v0.2.2:

Minor change to CSS markup to prevent interference with some versions of Mefi Navigator script.