excellent great list I will add them. I came across a blog to day with their groups listed so I might put that at the bottom under groups when I add the groups or maybe even a group widget on its own. I missed del.icio.us off too...

As for an alternative for the iframe, I am working on this too, I will do a flash version and a JS version. I could generate an image for forum sigs but the user would have to link to a profile page on the site.

thanks for the feedback.