Third-party JavaScript widgets (think Facebook Connect or Twitter Widgets) add functionality and enhance user experience, at very little cost to you.
Unfortunately, much of the existing third-party JavaScript currently in the wild really, really sucks. It will slow down your page, screw up your layout, and steal your readers' secrets if you're not careful.
In this talk I'll cover common mistakes made while implementing third-party JavaScript, and then show an approach that's worked for me in many places.
Code will be shared and war stories will be told, mostly about the fun we had building Pinterest's suite of buttons and widgets.