Internal Microsoft documents have confirmed that Xbox LIVE is on its way to mobile devices.

The service, called “Xbox LIVE Games,” will be available on phones running Windows Mobile software. According Kotaku, the internal Microsoft brochure from December 2009 makes no mention of the service on other mobile software platforms, thus cutting huge chunks from the services potential userbase. Including Microsoft’s own Zune music player.

Information relating to the service was revealed last week, with the discovery of a job vacancy at Microsoft for a ‘LIVE Community Director.’ According to the ad, the role requires the development of Xbox Live “across a range of properties, from Xbox LIVE to Windows Mobile.”

Back in E3 2006 Bill Gates revealed ‘Live Anywhere‘, a service that promised to allow access to Xbox LIVE from a range of devices, even suggesting the possibility of cross-platform gameplay. While the chances of playing Halo 3 Team Slayer on your phone against people on their Xbox 360’s is still just a fantasy, Xbox LIVE Games goes at least some way towards realising Live Anywhere’s potential.