Nokia has made a HTML5 based version of their Ovi Maps which can be used on other mobile platforms even iOS and Android. The reason behind this could be the deal between Microsoft and Nokia where Nokia claims that they will make some of their technologies, including Ovi Maps available to other manufacturers of Windows Phone devices.You can access the maps (m.maps.ovi.com) from your mobile device browser. While the service is still in beta, there is a good possibility of quick updates from the Nokia Maps team, ensuring that this would quickly become an alterate to Google Maps which dominates the market. Since Google Maps does not offer navigation in some countries, this allows Nokia the chance to take a step ahead with their offering.
You can head over to HandHeldBlog to see Nokia Maps in action on various devices including the Galaxy S2 and the iPad.