I think Circles is the killer feature. The public circle can essentially become your blog - anybody can read it. Then under that there are multiple layers where different groups or even individuals can see only what you want them to see.
You can send a private message - just specify an individual user when doing the update and the only person that will be able to see it is that user.
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My son, who is homeschooled, is doing a biology course from there is fall, and an Econ course from Utah State Opencourseware.,
I think Circles is the killer feature. The public circle can essentially become your blog - anybody can read it. Then under that there are multiple layers where different groups or even individuals can see only what you want them to see.
You can send a private message - just specify an individual user when doing the update and the only person that will be able to see it is that user.