If your blog is hosted on Blogger.com, you are ready to go but other websites will have to upload two files on the web server – one for gadget functionality (canvas.html) and the other for security features (rpc_relay.html).
As a user visiting friend connected sites, you can become members of sites and interact with other members who share your interests. You can also invite your friends from orkut, Google Talk, and other social networks to join the community. No need to create a new account for the site: simply use your Google, Yahoo!, AOL, or other OpenID account.
To know more, refer to the Friend Connect support site.