It’s available for Android, Symbian, Blackberry and Windows Mobile and will be available for iPhones soon. On PC there’s an iGoogle gadget available for tracking your contacts, but no desktop client for updating your location so far.
There doesn’t seem to be an API for updating or sharing location data, which seems like an enormous oversight and severely limits its utility. I’ve always considered the Fire Eagle concept of a location broker rather smart (even if somewhat scary) and the only logical and viable way to move forward in this space. Kinda funny how Yahoo! built a useful location broker service without any kind of useful client, thus making it difficult to adopt, while Google built a great number of clients, but no valuable service to take advantage of the collected data.
Should be interesting to see how this impacts Fire Eagle, Plazes, Brightkite, Loopt, &c. Probably not that much, as I have a really hard time imagining anyone using any of these services, except for the odd oversharing, exhibitionist early-adopter technophile. You don’t have to be a privacy nut to find the prospect of sharing one’s whereabouts with the internet scary. Compare with this Wired article on the dangers of location sharing and awareness, where it becomes obvious how dangerous posting location-tagged photographs on flickr can be, yet how inconspicuous and harmless the act seems in comparison.
Related: The luxury of privacy. Giving up one’s privacy isn’t just a matter of comfort anymore (if it ever was), it is a matter of economic well-being. For the economically weak it might as well turn out to be a matter of survival.
Related: Hello There: A CoreLocation Tutorial.
Related: DIY coarse grained location awareness using readily available rfid readers. Sorta IM-like presence for the real world.
Related: Pocket Life, seems like pretty much the same thing as Google Latitude, somehow affiliated with Vodafone.