YesScript

YesScript lets you make a blacklist of sites that aren't allowed to run JavaScript. Use YesScript on sites that annoy you or hog your system resources. One click to the icon in the status bar turns scripts on or off for the current site.

Unlike NoScript, YesScript does absolutely nothing to improve your security. I believe that Firefox is secure enough by default and that blocking all scripts by default is paranoia. YesScript strives to remove hassles from your browsing experience, rather than add them.