I was thinking about something similar to this, more like the swipe-for-options menu in Twitter for iPhone, and showing the same toolbar that you get on the details page.
I also really like the idea of double tapping -- maybe (instead of Instapaper) for the article directly, as a shortcut to avoid loading the comments if that's not what you want.
I was simply suggesting that you can use those actions in the app and randomly assigned what they should do. I like the double tapping for the article directly idea a lot.
I think the details toolbar is more useful where it is since I generally don't flag or upvote an item unless I read it. But that is a great idea (the swipe-for-options). You can include adding to Instapaper, and perhaps twitter/facebook/email sharing.
Also, a small bug: All the comments on the submissions say 0 points.
