Microsoft isn't used to being number two and while Mac and Linux offer up a bit of competition in the operating system wars, the threat to Windows is much more heated in the mobile industry.

Microsoft and LG Electronics today said they had signed a preliminary agreement on strategic collaboration in mobile technology in the hopes of Windows Mobile continuing to challenge the Symbian platform (Nokia's OS that is currently installed on some two-thirds of all smartphones).

As if Symbian wasn't enough to worry the very competitive Microsoft, Research in Motion's Blackberry systems and Apple's iPhone are also proving threatening. Even more forthcoming is news that several manufacturers are planning (or have already developed) smartphones based on Google's open-sourced Android software.