updated 12:50 pm EDT, Tue September 20, 2011
Google Plus now public with mobile video streams
Google+ received a shot in the arm Tuesday as Google took it out of its invite-only phase to make it public and push into mobile. The newly opened-up social network now includes video chat Hangouts on phones: any active Hangout works in the same drop-in, drop-out approach as it does on the web with several at a time. Support already exists in the Android app (Android Market) and is coming soon for the iPhone app (App Store).
A matching Hangouts API for developers will let the video chat feature integrate with third-party apps and sites.
Mobile users also see Huddle relabeled as Messenger, in a possible nod to Facebook's earlier service, also with support for photo sharing. American and Indian users can post updates and group chat messages through text messages, with more countries coming. Previously web-focused features like +mentions inside posts or +1 votes for comments now work on the smartphone.
Minor changes include profile photo editing on the road, more flexible notifications, and (on Android) the option of moving Google+ to an SD card to allow for more space for Instant Upload photos.
Although it's currently only on the web, Hangouts can now also serve as public live streams through Hangouts On Air. Much like Justin.tv or Ustream, users can turn a regular Hangout chat into a public broadcast recorded for posterity. Extra sharing formats work as well, including direct screen sharing, a sketch pad for drawing, Google Docs viewing, and specially named Hangout rooms.
Google+ now has its own filtered search feature and will let users look just for people, posts, and shared content.
Every feature should be available worldwide within the next day.