This is frick’n awesome. Dan Bartholomew has implemented a CardSpace module for DotNetNuke which allows users to submit a cardspace instead of creating a login. With this module now available I reckon a lot of the DNN sites out there will adopt CardSpace in a big way and it should really help drive adoption. The experience was a lot easier than registering yet another password for another site.
One suggestion I would make is when the CardSpace image is clicked on the login page, turn it into an animated GIF. The CardSpace selector can take a few moments to come up on some systems so this will stop people clicking repeatedly and potentially getting frustraited.