Cell phone to satellite
TerreStar Networks (external link) recently announced they will build the first satellite to communicate directly with cell phones. Operational at the end of 2008. They hope to provide cellular radio service to communities and areas that have no cell phone coverage now. A few points:
1) Four years is a long time to wait for a radio-telephone;
2) As with all sat phones, you'll need a view of the sky to get a signal. The phone won't work indoors unless you have an external antenna;
3) You can get a wireless connection right now through providers like Globalstar (external link) Call from nearly anywhere in the United States or Canada. Their phones default to cellular radio if a signal is available. You'll save money in many cases by not using the bird. Speaking of money;
4) Satellite phone service is expensive. But, adjusted for inflation, it isn't more costly than roaming charges were for cell phones ten years ago. And being able to call from nearly anywhere is worth a great deal by itself.