Cell phones and other gadgets that can be charged by USB have already proven themselves to be more useful than traditional wall chargers. There are so many phone models and electronic items that it is possible to have a business that only sells chargers.
The following excerpt is from a press release from the GSMA, an organization that represents the interests of the worldwide mobile communications industry:
The GSMA and 17 leading mobile operators and manufacturers announced (on 2/17/09) that they are committed to implementing a cross-industry standard for a universal charger for new mobile phones. The aim of the initiative, led by the GSMA, is to ensure that the mobile industry adopts a common format for mobile phone charger connections and energy-efficient chargers resulting in an estimated 50% reduction in standby energy consumption, the potential elimination of up to 51,000 tons of duplicate chargers, and the enhancement of the customer experience by simplifying the charging of mobile phones.
The group has set an ambitious target that by 2012 a universal charging solution (UCS) will be widely available in the market worldwide and will use Micro-USB as the common universal charging interface. The group agreed that by the 1st January 2012, the majority of all new mobile phone models available will support a universal charging connector and the majority of chargers shipped will meet the high efficiency targets set out by the OMTP (Open Mobile Terminal Platform), the industry body who developed the technical requirements behind UCS.
http://www.gsmworld.com/newsroom/press-releases/2009/2548.htm