The company introduced 19 new social gadgets as part of the launch. In a sense, the only difference between the previous gadgets for an iGoogle page and these gadgets is that friends with the same gadgets can see your updates and even engage in a game with you.
In a blog post announcing the new gadgets, the company said:
Social gadgets let you share, collaborate and play games with your friends on top of all the things you can already do on your homepage. The 19 social gadgets we're debuting today offer many new ways to make your homepage more useful and fun... Your friends are able to see what you share or do in your social gadgets either by having the same gadgets on their homepages, or through a new feed called Updates. Updates can include your recently shared photo albums, your favorite comics strips, your travel plans for the weekend and more.
The rollout to users is gradual, so don't be surprised if you don't see the gadgets on your iGoogle page right away. As usual, Google created an animated YouTube video to help explain how social gadgets work.