If you open many tabs in Safari for webpages that have Flash content, you've probably noticed Safari's processor usage skyrocket.
clicktoflash is an open source Safari (WebKit) plug-in which prevents Flash loading unless you click the graphic representing the Flash content. I find Safari is much more stable as a result and quicker at loading webpages.
[
robg adds: An
earlier hint discussed using SafariStand to do the same thing. SafariStand, however, is a complex add-on that many users may prefer not to add to Safari. clicktoflash does just one thing, and after testing it for a day or so, I can say it works quite well. In Firefox, I use the
FlashBlock plug-in to do the same thing.]