Founded in 2005, Plazes lets "friends" update each other about what they are doing when and where, resulting in a Twitter-like activity stream but with integrated geo-tagging. Users can then subscribe to any of their friends' activity streams or to groups of friends, as well as to specific locations known as "Plazes". Updates can be done either on Plazes.com or by mobile phone (via text messaging) or using a number of third-party applications that utilize the Plazes' publicly available API.
Now that Nokia has acquired the service, "if all goes well" we can expect Plazes to be "made available to millions of Nokia customers both online and on millions of mobile devices", according to the official Plazes blog
A few key takeaways from the announcement...
Moving forward, it's clear that mobile, combined with location, represent the next social networking frontier. As evidence, Google's Android developer contest is littered with location-based social applications, and the official iPhone SDK has already given birth to a number of location-aware social networking apps. What's not clear yet, however, is whether the eventual winners will be established social networking services such as Facebook or Twitter that add location-based functionality or newer or specialized entrants who build in location and mobile from the get-go.