Google announced yesterday another step in what its engineers see as that inevitable evolution. A new, free service from the Mountain View, Calif., tech giant will allow any Web site to become a social site.

Any Web page, whether it is devoted to curling or pizza or a folk singer, could allow visitors to meet and connect with “friends” who visit that site. Like any such major network today, a Web page using the service could present users with the names and pictures of friends and potential friends. Those people could then post messages to one another.

The new Google service, known as Friend Connect, raises the possibility that the kind of kibitzing that has been largely contained on a handful of mega-sites could spread across the Web. <