Facebook Connect is being implemented across many web sites, but Facebook has been pretty quiet about how big the service actually is. Today, it’s sharing a few more pieces of information.

More than 80,000 “web sites, devices and other services” are running Connect now, a big increase from the 15,000 that the company had previously disclosed. And, when matched with numbers from analytics firm comScore, half of the 100 largest web sites in the world and two-thirds of the largest 100 web sites in the US have implemented Connect. You can see an especially striking example of Facebook Connect on The Huffington Post news site.

And, more than 60 million people “engage” with Facebook Connect every month via external services, according to the company. Facebook says it defines “engagement” here to include logging in to a Facebook Connect site and sharing content via Connect, so it doesn’t include people who visit the sites but don’t use Connect.

Facebook has focused on improving Connect and pushing it out to more users. The core service launched around a year ago, with more recent features including Connect for iPhone and for desktop applications, for gaming consoles and most recently for mobile devices.