Userscripts.org

Show/hide the header, footer and sidebar tabs on iGoogle to save space! Perfect for small screens or netbooks!

Adds reply and reply-to-author buttons to Google+ comments

Makes thumbnails cycle though the 3 previews. Additional feature to view all thumbnails on mouse hover, and move off to hide them.

Automatically pauses the video when you switch to a different tab or window, and automatically plays when you come back to it

Adds buttons to top-left of FB page for hiding/showing the sidebar/chat/ads from view. Script compatible with Greasemonkey/FireFox as well as Tampermonkey/Chrome. No reload of page needed to hide/show.

Change page's color scheme to optimize for watching videos. Can toggle on/off with a hotkey

Add toggles for showing/hiding @replies and #hashtags on twitter.com and brizzly.com

A simple script that uses a key press "S" to toggle the GMail searchbar. Inspired by this great script... http://userscripts.org/scripts/show/50486

Dim the Lights and watch your video in peace. Auto Dim lights setting (statusbar icon menu config). Works with Firefox, Chrome and Opera! Currently testing, Working well. Try it.

Creates a set of links for all of your Yahoo Fantasy leagues. You'll need to customize it with your league names and IDs. (Links replace the "Make Y! your homepage" link at the top...but seriously, who cares about that?)

adds a big button on the left of the page to quickly hide and pause the video in 1-click.

Auto-load more comments. Click "Auto Load Comments" and more comments autoloads. Click "Stop" to stop loading. Toggle comments by clicking the Toggle Comments button.

Cleans up image and video galleries, leaves only thumbs. They can be individually toggled for download. - Complete application!

Use this GreaseMonkey script to reclaim the hefty area that the GMail's searchbar and Logo area take up.

Enables inline image expansion for all images. Should play nicely with userscripts that modify the DOM after it has been loaded.

Allows Toggling of Youtube Comments via button. It has options now! Chrome, Firefox should both work.

Add multimedia keyboard support for Grooveshark (play/pause)

Changes the background color of a page and also the color of text & links to make pages easier to read. Use F2 key to toggle the colors on and off.

Toggle toy or game items on Tanga (tanga.com)

Toggles Un/Read Mail at Indamail.hu

Allows you to toggle between showing member items and not

Adds MBTA map functionality to Google Maps.

Toggle sidebar on/off on mozwiki and devmo

Fixed-font message bodies toggle for GMail (new UI/API version)

Lets you hide add-ons you don't want to see

Provides a link on the page or userscript command to enable/disable this script easily

Allows you to hide elements by double click

Tons of assorted developer functions ranging from button removal to element fade-ins to advanced xpath grabbers.