What are windows 7 online ID providers?

Information extracted from this tutorial on a totally different subject: Streaming Your Windows Media Player 12 Library Over the Internet

The online ID provider software simply lets you link one of your online accounts (such as the one you use for email and instant messaging) to your Windows 7 user accounts. For now, you can only link your Windows Live account, but there are plans to roll out other online ID providers (such as Google, OpenID or Facebook).

Later update: I recently published a tutorial which explains everything there is to know about Windows Live ID, including the services and apps that use it. You can find it here:

Simple Questions: What is Windows Live ID?

I hope this is helpful.

It appears that Windows Live Mesh (which is a part of Windows Live 2011 package) also uses Windows Live Online ID provider in order to synchronise directories and settings over Internett across different computers.