For a good introduction to Locative Media try headmap.org
For related developments and news try smartmobs.com
‘Locative media’ describes the theory and practice of what used to be known as augmented reality (AR). It is distinguished from its earlier incarnation by its focus on social interaction and consumer level mobile, location aware devices.
A few simple examples of Locative media are:
– Tagging digital media with place information so that media can be ‘found’ at a given place.
– Connecting social networking tools to location information, so that you can find your ‘closest’ friend.
– Sharing information about places so that you can ask questions about the place you happen to be at, and get answers from people who have been there before.
– Social interfaces to places.