Facebook’s “Like!” button, the Flattr button and plenty of other widgets work pretty much the same. You either create some IFRAME
directly (Facebook non-XFBML method) or include some JavaScript which then injects the IFRAME
into your DOM once it’s ready (Facebook XFBML, Flattr). The widgets provide you with some cool social one-click-functionality. That’s nice and easy… unless someone’s planning to mess around with it.