Recommended Handheld Device for WLAN Application

Recommended Handheld Device for WLAN Application

We are in the process of developing a software suite which will allow users within a building to connect to a server (a database or a web service) hosted on a LAN using a .NET application. We're looking for suitable handheld devices (preferrably running .NET) which are capable of connecting to the LAN wirelessly. A touchscreen interface is preferrable.