Seems the button-meme meme simultaneously infected a few of us the other day.
Over at mod-pubsub, just the day before Scoble's post regarding the RSS button meme, we created a new button for use on pages/projects that utilize mod-pubsub, and introduced it in precisely the same way, as a meme. [If you don't know what mod-pubsub is, go check it out - in short, it is asynch pubsub using web standards, a very RESTian approach, enabling some message exchange patterns you may not have thought possible today on the web]
This may have been more than coincidence - I think there is some deeper magic at work beneath Microsoft's technology roadmap (especially Indigo), and what it means for web technology purists. More to come on this.