Login on Microsoft Community Server websites
I don’t know if you can find them, but I have no idea how to get to the login page and/or register account page via some link, on weblogs.asp.net and blogs.msdn.com. A lot of blogs have anonymous comments turned off, therefor you might want to register or login. Another reason is subscribing to new comment, so you’ll get an email when a new one is added.
Luckily they’re using Community Server, so those locations are the same everywhere. If you want to know, these are the locations.