Last Friday, Aug. 7, I tested and wrote in detail about the iGoogle social gadgets Google launched in Australia.

These social gadgets and more are gradually becoming available to the millions of U.S. iGoogle home page users this week, allowing people to play games with each other and share news content and to-do lists from their iGoogle Web pages.

While only 13 gadgets are available on the site targeted for the land down under, there are 19 on the U.S. Google social gadget site as I write this.

In addition to the "Who Has the Biggest Brain?", "Chess" and "ToDo" gadgets offered in the Australian-tailored version of social gadgets, the U.S.-flavored site offers gadgets for NPR, The Huffington Post and games such as Scrabble.

Check out the video demo of how to share the gadgets here:

You can also take a reading tour of social gadget features here. Both the video demo and tour are nice, but neither adequately explains how to start using social gadgets from the top down.

For example, the video tells you how to accept gadget invites, but not how to activate the gadgets. How does Google expect users to understand gadgets without more clarity?

That's found here from a support page on iGoogle:

There may be some concerns about gadget controls, that is, how to render content shared in the Friends groups and Updates feeds invisible to users. Google does a good job explaining the Friends function in its tour of the gadgets:

If you click the Friends link in the left side bar of iGoogle, you can add people you're friends with to your Friends group. Contacts can be moved in and out of this group at any time, and this is the only group of people who can see your updates and with whom you can share social gadget activities. Similarly, you can see someone else's updates or social gadget activities only if they have included you in their Friends group. You can order your friends group however you want. They won't get any information from you unless you specifically share a gadget or content with them.

Google also does a good job explaining how Updates works:

Clicking the Updates link in the left side bar shows you a feed of activity that both you and your friends have shared via the social gadgets on their iGoogle page. Updates show up automatically if you're signed in to your Google Account and have friends that use social gadgets on iGoogle. You can turn off your gadget updates by going into your gadget settings.

Basically, just uncheck the Friends group and Updates boxes for any gadget you don't want to share:

That's simple, the way sharing ought to be. Although how these social gadgets will help Google tackle social network rivals Facebook and Twitter is unclear; those sites are socially organic.

Google is bolting on social tools to a traditionally siloed personalized Web page. In other words, the audiences for this kind of thing are at Facebook and Twitter, which boast over 300 million users combined. More than 100 million users are at MySpace.

Why would they come here to be social?