Google announced a number of changes and additions to its social services at this year's I/O conference, and its continuing to enhance its offerings, going public today with a new recommendations service for the +1 sharing button. Now when users hover over the Google +1 button on a given site (for example, the one to the left of this article), they'll not only be offered the option to share the item via Google+, but they'll also be served recommended content on the same site. The new button, which has been undergoing testing the past few weeks, also uses the activity of those in your Google+ network to help surface items it thinks will be most relevant to you. The pairing of on-site recommendations — which could encourage extended browsing time as users explore — with social sharing features could make the +1 button an even more attractive option for websites to include in their arsenal, and we wouldn't be surprised if the change helped spur additional adoption in the months ahead.