Responsivator!
See and share how web pages look at different screen sizes
by @johnpolacek
With Responsivator!, you can paste in any page and see how it looks at various screen resolutions.
Now, say you want to share this page. Just copy the link from the share field and send. If you want to hide the header & controls, just check the box and you will be able to send a link that is nice and clean with just the frames.
Responsivator! is built upon fine work done by others like Matt Kersley, Benjamin Keen and lensco.
Responsivator! also uses 2 jQuery plugins, also created by @johnpolacek - jQuery Framer and jQuery Configurator - so check those out too.