A web-based card sorting tool

A while back I posted an entry here about Uzanto’s MindCanvas, an application for doing user research. A week or so ago, Cody Burleson of IBM Global Business Services posted a link to the IA Institute members mailing list about a web-based card sorting product called Websort. I haven’t tried it out, but it looks like it could be useful when you can’t do card sorting in person.
Following up, Lou Rosenfeld points out that Donna Maurer, who is writing a book on card sorting for Rosenfeld Media, is maintaining a comprehensive list of card sorting tools.