cellphone GPS coordinates

We need an application that can connect to the GPS modules? running on the following cellphones and by the click of a button gives you coordinates and address information available: HTC Touch diamond 2 Samsung i900 (Omnia) Apple iPhone 3G 16 GB The application interface must have? 2 text boxes and a button. When clicking the button the current? address information must be in the one text box and the current GPS information must be in the other text box. We will also consider bids that can cater for one or some of the phones.? Please indicate which phones you can support. The system must be written in Microsoft.Net c#