Lots of entrepreneurs have great ideas for the mobile phone–from turning it into a biometrically enabled payment device that will allow people to stop carrying all their plastic cards with them to targeting ads to Saturday shoppers. But thus far there isn’t a clear catalyst who can ignite the mobile phone ecosystem. As I discussed in my keynote to the “Marketing the Mobile Channel” at CTIA last week, contenders include Apple with its iPhone entry, mobile operators that are still weighing the pros and cons of openness, and, of course, Google.

Today, the Wall St. Journal reported that Google is going to introduce Google-powered mobile phones mid next year, all based on an open operating system and a suite of Google apps. The search-engine behemoth has a great business case for getting into mobile phones–loaded with content (including maps and navigation to lead you to places to buy things) it is a great place to insert ads; and the resulting revenue stream can support a lot of free things.

However, Google faces the same difficulty that other developers have faced–which is interacting with the mobile carriers who understandably want to get paid for their vast investments in mobile capacity. So where would you place your bets–the iPhone, Google, Microsoft, an operator, or none of the above–in setting the mobile phone space on fire?

Download my CTIA presentation to stimulate your thinking.