Socialthing!, developer of an application that helps users manage their various online social networks, announced Monday that it is launching a private beta for its Web-based service. The Boulder, Colo.-based startup noted that it is debuting the service at the 2008 SXSW Interactive Festival, which is part of the annual South by Southwest conference being held this week in Austin, Texas. Socialthing! said it is also unveiling the beta version of its iPhone service, which offers iPhone users the same functionality and benefits of Socialthing's Web-based service. Socialthing! is venture backed by eonBusiness.