The first generation of wireless cellular communication technology, called Analog Mobile Phone Service (AMPS), is known as 1G. Introduced in 1981, it enabled users to place calls without an operator and used analog radio signals to pass calls between cells.

Second-generation technology (2G) introduced digital cellular in 1991, enabling data services, including the ability to send and receive pictures and video. Digital also enabled access to webpages written in Wireless Markup Language (WML) via a browser, based on Wireless Application Protocol (WAP).

Third generation technology (3G), introduced in 2001, offers wide-area wireless voice and video telephony, as well as broadband wireless data access, and is much faster than previous technologies. 3G networks should not be confused with short-range wireless data networks which are based on the IEEE 802.11 standard and commonly known as Wi-Fi or wireless local area network (WLAN). Newer mobile devices can often connect to the web via one or more of these networks for data access.

Finally, 4G, or fourth generation, is expected to provide faster, higher-quality services including Internet Protocol (IP) based voice, data, and multimedia.
Listen Jeff Hawkins, Founder of Numenta, was an early observer of the idea that people wanted their primary personal computer to be in their pocket, thus he launched Palm in 1992. The self-described “reluctant entrepreneur” says that he never intended to launch a mobile computer industry (or any company, for that matter) and he describes how he negotiated a limited, part-time relationship with the company, despite the hopes of his investors. He describes in detail the organization’s first big failure and its first huge success with the Palm Pilot, and a timeline of the company at large.

Whole themes of that discussion are:
The potential of mobile marketing,
What is expected of them, and where the difference between mobile marketing and mobile advertising
The potential of mobile content and mobile campaigns.

Link to interview the http://media.podcastingmanager.com/72206-80605/Media/Mobile% 20Marketing.mp3

 Company Total
    Google Inc. 62.48%

    Yahoo! Inc. 33.54%

    Microsoft Corporation 33.36%

    AT&T Inc. 21.22%

    Time Warner Inc. 19.06%

    The Walt Disney Co. 17.00%

    News Corporation 15.54%

    Sprint Nextel 15.29%

    The Weather Channel 15.28%

    eBay Inc. 14.19%

 Company Total

    Google Inc. 30.94%

    Orange 21.68%

    BBC 20.90%

    Microsoft Corporation 17.75%

    Vodafone 16.79%

    eBay Inc. 13.08%

    O2 12.77%

    Hutchison Whampoa 12.67%

    Yahoo! Inc. 10.97%

    Deutsche Telekom AG 10.71%

While I was not surprised to see Google at the top.

For more detail look in http://www.marketwire.com/2.0/release.do?id=745416