New categories of handhelds have emerged and been rapidly adopted, such as ereadersAmazon's Kindle and Apple's iPad. Wireless hotspots to connect to the Internet are everywhere in urban areas and on transportation lines, and access to highspeed 3G and 4G networks has made interoperability a standard, as you also read in Chapter 1. Consumer and enterprise apps for mobile computing and commerce continue to expand the capabilities of this in-demand technology.