I found the weather floatbox in the demo page. That's really cool.
I know it need to find the users location but I don't know how to do that.
I see in the demo it's calling Weather.php from their own site.
Is there a way for me to put one like this on my site where it will look at the users location and bring up his weather?

This float box works good but I need a script to call their local weather.

<a href="http://forecast.io/embed/" class="floatbox" data-fb-options="type:ajax width:666 height:245 boxColor:#123456|#edca98 contentScroll:false">How's Your Weather?</a>

I'm not going to provide server-side code for your site content. I can tell you that I get the IP address to geo-location data from the http://ip-api.com/ API, and then request the weather for that location from http://forecast.io/ as an HTML embed.