Google has released the first taste of what will become a larger Google+ API for third-party applications built on their social network. So far, all you can do is authenticate, retrieve someone’s public profile, and read their public activities. That doesn’t sound like much, does it?

Well, here are some ideas I came up with over lunch:

• Add Google+ activity to a lifestream.
• Allow someone to comment on your blog using their Google+ identity.
• Create a map of movements of based on public checkins.
• Analyze posting frequency & times.
• Analyze most popular posts based on reshares, +1s, replies (basically: add Google+ to Klout [Update: That was fast!])
• Associate a person with other profiles you might have from other social networks, based on their profile URLs.
• Build a list of people who work at an organization and speak a particular language.

Of course, it’ll really start taking off when they enable write access and the link-sharing and cross-posting services can get in on the act.

So, how about you? What else do you think can be done with the limited API released today?