programmer

Hello everyone!

Does anyone can give me a hint or any ideas about a valuable project with the following specifications:

1) It should be a web service project.
2) It should enhance the mobility (i.e. this will help people using many kinds of devices such as: Pocket PC, Smart Phones, Tablet PCs....) since I want to do it using ( .NET technology)

Thank you.
Waiting for your valuable suggestions...