With location based services the latest “next big thing” it’s interesting watching the major and minor players slowly set out their stall to end users and developers. Today it’s the turn of Google, as they announce the public API for their Latitude service.

The current big names in location services, such as Gowalla and FourSquare, work around the concept of checking in at a location and earning credit for being there while building up a database of your favourite spots alongside a game engine that allows you to earn badges and kudos by checking in to new places or claiming ownership of a location.

Latitude currently has an eye on providing a more personal service, asking not only where you are just now, but finding out where your friends are. Where the LBS games focus on the locations themselves, latitude is a much more personal experience for the user.

As with most API’s there are likely to be new clients and improved ways of checking in alongside more innovative and off-the wall uses. I suspect we’re all waiting to see what mad ideas will join the obvious ones around location.

More on the API at Google Code and the Google Blog.