Judging from the top players in the market Apple, Google -- which last week for its hardware and patents for $12.5 billion -- and RIM, the answer seems to be no, you really can't.

Yet, during the past two years Google's Android OS has exploded in popularity to become the number one smartphone OS. It currently , according to market tracker comScore. Yet Google did all this without owning any hardware. Knowing that this growth probably won't last forever, Google took matters into its own hands and bought Motorola Mobility.

Although the smartphone market has expanded like wildfire, the market share for Microsoft's Windows Phone 7 OS remains tiny. In the U.S., Windows Phone 7 market share is down to 5.8 percent as of June 2011, according to comScore.

So what is Microsoft to do? Continue its long, storied history of licensing software to hardware partners -- which has clearly worked well in the PC space? Or do as others have done and buy a phone maker? The likely acquisition target is Nokia, and the two companies already have a "collaboration agreement" that will have Nokia running Windows software on all its phones starting later this year.

Industry analysts are divided on whether Microsoft should take the plunge and buy Nokia or continue its partnership and license WP7 to other hardware makers like Samsung and HTC.