The term “Responsive Web Design” was coined by Ethan Marcotte, in an an article published by A List Apart. Loosely defined, it means adapting to various screen sizes, using a fluid grid and @media queries in CSS.
When should you use RWD™? Responsive web design using @media queries (with one codebase for all devices) typically works best for web “sites” (not apps). Apps work best when tailored to one particular interaction paradigm. For instance, mobile Gmail is a different experience than on the desktop. As a general rule of thumb, if your content can be read via RSS (such as Google Reader) and still make sense, it might be worth considering a responsive approach.
The one thing all these phones have in common (besides Angry Birds) is they all have decent web browsers. http://paulirish.com/2010/high-res-browser-icons
Disney.com — Entire site is responsive There is one Flash ad, which disappears if the browser is at “mobile” width. Note: Most mobile devices have little/no support for Flash, Silverlight, etc.
http://trentwalton.com/2010/07/05/non-hover Elements that rely only on mousemove, mouseover, mouseout or the CSS pseudo- class :hover may not always behave as expected on a touch-screen device such as iPad or iPhone. — Apple Reference Library