Supports the latest Firefox + Greasemonkey and Chrome + Tampermonkey.

You can tweak which elements the script hides by deleting lines in globalElements or editing sidebar block headers in sidebarBlocksGood (all other blocks are hidden; applies only to movie/person pages). It also removes the IMDbPro button, you can remove the relevant line in the script's source code if you need it.

Example: before / after (clickable)