Somebody know how to use live tiles with Phonegap and Windows Phone 7?

I'd like to know how to load some live tiles from a JSON from an URL but I have never used that option, could somebody give an idea of how to do it?

Live Tiles are not supported by the PhoneGap 'core', in other words, if you want to use this feature it will not be cross platform. In order to support platform specific features PhoenGap has the concept of plugins. You can find the live tile plugin here:

https://github.com/purplecabbage/phonegap-plugins/tree/master/WindowsPhone/LiveTiles

As per the docs, you can update it as follows:

navigator.plugins.liveTiles.updateAppTile(success, fail,
                  {title: 'title',
                   image:'Images/appbar.next.rest.png',
                   count: 5,
                   backTitle: 'Back title',
                   backContent:'Back side',
                   backImage : 'Images/appbar.close.rest.png'});