The NoScript extension provides selective execution of JavaScript and plug-in code based on a whitelist. NoScript partially works with Conkeror (handling of <embedded>-tags (flash uses this) do not work). Conkeror comes with a glue code module for noscript that provides some basic commands to use the extension. To activate it, put this in your rc:
require("noscript");After performing the above require, a function M-x ns-toggle-temp is defined, which will enable/disable javascript for the current site/page after prompting for confirmation.