Dont kow if they can now, probably in the "on portal" non-open apps and I would guess through a proprietary site/connection.
I see this as being key to the future. With an open-source phone, web apps can be designed to access the phone's gps (and other phone related) info.
This is the future of and a big benefit of mobile web. GPS data integration. But it must be open source. i.e., as a web developer, you use a snippet of code <get$ local> or whatever in your website code and on any phone using open ops system or browser X, it returns the geo location of the phone. You then use that to map things around them and help them find something. (note: im not a programmer!). Note this could happen on .com or .mobi or whatever....the the "cleanest most efficient" coding would hopefully be required of a .mobi.
I've focused a lot of my domain investments on this thought.