If you run a blog or a website, you might have heard about Facebook Connect and the possibility of using it with the WordPress blog system. Basically, Connect is Facebook’s attempt to spread their identity system across the rest of the web. By integrating connect, you can use Facebook’s user system, comment system, etc. on your site. You give a lot of power and leverage to Facebook over your website but it could make interacting with your site a lot more attractive and easier for users.
Their first widget allows you to use Facebook Connect to add commenting functionality to your site or blog. Here’s some Facebook developers explaining it all…
A quick tutorial by Facebook engineers on how to create a Comments Box social widget quickly and easily for iframe applications and websites.
I made a proof of concept of something similar about 8 months ago.