With mobility having transformed from novelty to necessity, millions of Web sites are being optimized to better serve users who access them via mobile devices. The mobile devices people use to access these sites are also changing. Laptops and tablet PCs remain common, but more than ever, people are surfing the Web on their smartphones, using preinstalled mobile-browser software. In many cases, this software is proprietary, and depending on a user's network or location, Web browsing speeds can vary wildly.

Interactive Map: Rating the States

Chad Vander Veen  |  Associate Editor