"You can now browse your friends’ Liked items to find great articles to read." Instapaper now has social functionality, but it looks like just the right level of sociality for the product. I mainly use Instapaper on my Kindle, now, but will be sure to hit "like" on the stuff I'd recommend from the website. Now: to get Instapaper likes into Stellar?

Revish: a site for "reading and sharing your reading experiences". Social, shared, API\d up. Looks interesting.