The W3C (in collaboration with OMTP BONDI) is developing standards for device APIs, with a focus on mobile devices such as cell phones. There is a separate Device APIs feature request for the general notion of a complete set of device APIs support in browsers. This feature request is for one particular set of device APIs around geolocation to judge the importance of this particular feature. The latest W3C spec for geolocation APIs is at:
The geolocation APIs have their own Working Group at the W3C and some browsers (Firefox 3.5, WebKit, Opera) are already shipping support for this feature.