I couldn\'t find anywhere (if it\'s possible) how to resize the whole like button (not it\'s iframe or the container, but the button itself with the writing and everything).
Although you say not the iframe, if you do scale the iframe with CSS3 it will increase the size of the button. It would probably be best to give the iframe a ID or class but something like this would work if it was the only iframe on the page:
iframe
{
transform: scale(1.5);
-ms-transform: scale(1.5);
-webkit-transform: scale(1.5);
-o-transform: scale(1.5);
-moz-transform: scale(1.5);
transform-origin: top left;
-ms-transform-origin: top left;
-webkit-transform-origin: top left;
-moz-transform-origin: top left;
-webkit-transform-origin: top left;
}
Here is an example http://www.tinydesign.co.uk/like/