Add line numbers to lines within CODE elements nested within PRE elements (the format for code snippets on many developer-oriented sites)

Alt+clicking and dragging across a text fragment will trigger Ahoy and furnish you with an Ahoy link to your selection.

Un-crapifies TechCrunch so that you can get your rumors and baseless speculation without the gunk.

Removes the advertisment iframes at the top and bottom of Vox blogs.

Removes the annoying link ads and popup div tooltips triggered by intelliTXT link ads. As of August 2007, it also scrubs Kontera ads.

Makes it easy to gauge the relative sizes of the images on a Google Image Search results page at a glance.