the ability to run custom javascript within the page on a hotkey was a damn godsend, since all the bookmark toolbar plugins that used to let you do alt+whatever apparently can no longer execute bookmarklets that start with the javascript: prefix. a blessing in disguise because now i don't have to write these obtuse as hell double encoded javascript bookmarklets to do things like ninja videos out of their players - now i can do it with properly formatted scripting that is easy to update.