Formspring's new smile buttons are a lot like Facebook's "like" buttons: a generic vote of approval that doesn't require too much commitment from the end user.
The button appears beneath each post; next to it, you can see icons for each person that's "smiled" at that post. You can smile at as many posts as you like, but you can only smile at each post once.
If you're feeling narcissistic, you can smile at your own post, and if you're feeling grumpy or indecisive, you can "un-smile" a post, as well.
While Formspring's Q&A can be anonymous, smiles are linked to the user's account, making the site a little more social and a little less solely introspective. Because each profile will appear in the list of people who smiled a Q&A post, users are now exposed to a slightly broader circle of online acquaintances and friends.
Also, your followers will sometimes see your smiles in their feeds, and soon, everyone will be able to see your Formspring smile history.
Since yesterday's launch, the buttons have already generated 1 million smiles across the site.
Another recently added social feature is Formspring's respond button, which publishers can place on their websites to encourage a Q&A-format dialog around content.
Smile and respond buttons are hopefully part of the startup's path toward even more onsite interaction. Formspring tells us the company has plans to roll out more features and extensions over the next couple months; we'll keep you posted as news breaks.