I have subscribed to Visual Studio Online (old Team Foundation Service) using a visualstudio.com sub-domain name. My account is created using http://www.visualstudio.com/en-us/get-started/connect-to-vs.
It’s cool, I can use with 5 users for free. A real TFS in the cloud. There is also another solution that is to setup project on codeplex.com. It allow to have a TFS set up.