I hate the idea that I would be at my workplace without actually logging into my stackoverflow. I used to login to my stackoverflow account via Google id. But it has been blocked recently(All google sites). But yahoo is still allowed. I would like to login to my account in SO via yahoo. Is that possible? Can I change the login from Google to Yahoo?
You can add a new Yahoo login by going to your user profile page and clicking on the "my logins" link on the top right (below the Ask Question button). This will bring up a dialog listing your current logins. There's an "add more logins..." link on the bottom left of that dialog. Once you add a new login you can just stop using the old one or remove it.