Async Widget load

Hi all

Is it possible to load widgets asyncronously by default, pretty much how it works after user clicks "Save" after widget customization ?
Why do I ask: Some widgets (even default ones) become "too heavy" if misconfigured , so they may cause substential page load time and currupt user experience of the site. Usually visitors are much more tolerant to "Ajaxing" than to page remaining for several seconds.
Sample code will be greatly appreciated =)
Thanks !