Targeting/Developing for multiple mobile platforms with one programming language (C#)? Cost-Benefit?

Question

Today it is possible to use C# programming for multiple mobile platforms such as:

• WindowPhone7
• Android - Monodroid
• iPhone - Monotouch

Answer 1

The biggest advantage for me is the ability use reuse the business logic and communications code between mobile platforms. Yes, I have to write the UI over and over again, and it takes time to get your head around that, but at least my base platform is reusable.

In my experience when moving to a new platform, it takes me a lot longer to learn the UI framework than to learn a new language.