If you scroll down a bit to the left you will see the google friend connect widget
This is what over interweb overloads say about it
Bring viral social growth to your website
* Anyone can join your site with one click by using their existing Google, Yahoo and other accounts.
* Visitors can evangelize for your site by inviting their friends and publishing their activities to their social networks.
* Social gadgets will keep these visitors more deeply engaged with your site, and with each other.
anyway give it a go I will probaly get bored of it and take it down……. some time.