The companies want users to be able to use their Google and Facebook logins to enter third-party sites. It benefits users and third-party sites and allows Facebook and Google to collect more information about what users are doing online.

There are some key differences between the services. Google's service . This means sites using Google Friend Connect can use OpenSocial's open-source applications, such as message boards and ratings gadgets. Google also lets users sign in with their Yahoo!, AOL and MSN usernames.

It's also easier for site owners to use. Google requires adding a few "snippets of code to your site," . However, "adding Facebook Connect apps is a ," he said.

However, Facebook has an advantage in terms of partnering with large third-party services. Facebook Connect is already working with , and . Google Friend Connect's partners seem to be smaller sites run by individuals, such as and .

It's too early to say how either service will fare, but the Internet is already buzzing with early feedback from site owners.