Microsoft has officially announced the logo for Information Card. The reason for having a logo is that it creates recognition. People will immediately see that a website support logon with an Information Card. This is what it looks like:
You can download the logo package here. Obviously, the logo comes in different sizes. I've already updated the login for my website, but I hope the little twist is ok with the guidelines. If you want to watch a webcast on Windows Cardspace, there's one on June 29th.