These breakpoints seem chosen somewhat arbitrarily. I'd enjoy a longer post elaborating on why you chose them!<p>The seminal Boston Globe design chose 5 breakpoints based on rough hardware buckets, see <a href="http://www.flickr.com/photos/joshclark/6200745034/" rel="nofollow">http://www.flickr.com/photos/joshclark/6200745034/</a> (via <a href="https://twitter.com/globalmoxie/status/120157487797243905" rel="nofollow">https://twitter.com/globalmoxie/status/120157487797243905</a> ).