In addition to a few big features, yesterday’s release of iOS 4.3 brought several nice-to-haves such as password reentry for in-app purchases and the ability to comment on songs or like them directly in iPad’s built-in iPod application (no, not “like” as in “Facebook like”). The feature requires you to sign up for an account with Ping, Apple’s social network for music. Furthermore, it appears to work only with songs purchased through the iTunes Store, reports MacStories.net.

You simply run the iPod app on your iPad and play any iTunes Store-purchased song found under the Purchased playlist. On the now playing screen, tap once to reveal the controls and you’ll see the new like and comment buttons next to the Genius icon. Tapping the Comment button puts up a compose window where you can type in the post that will be shared with your Ping friends.

Here’s to hoping that Apple will tweak the like feature to include any song that matches the information on the iTunes store, like desktop iTunes. Ever since it was introduced, Ping has had trouble gaining traction.

We suspect this has a lot to do with Facebook pulling support for Facebook Connect in iTunes over fears that Apple was essentially attempting to push a social network of its own on the backs of Facebook’s giant half a billion community.