This snippet loads webfonts (in this case from Google Webfonts) asynchronously. This means it does not block page load but also means it can cause FOUT.

load-webfonts-async.js

WebFontConfig = {
	google: { families: [ 'Istok+Web:400,700:latin' , 'Lora:400,700:latin' ] }
};
(function() {
	var wf = document.createElement('script');
	wf.src = ('https:' == document.location.protocol ? 'https' : 'http') + '://ajax.googleapis.com/ajax/libs/webfont/1/webfont.js';
	wf.type = 'text/javascript';
	wf.async = 'true';
	var s = document.getElementsByTagName('script')[0];
	s.parentNode.insertBefore(wf, s);
})();