Those of you who use Twitter know how quickly one can accumulate unknown “followers,” people who sign up to receive updates on their Twitter pages whenever you post a Tweet. Unfortunately, it’s not uncommon to find that a number of those unknown followers aren’t really people at all, but fake profiles designed to draw visitors away from your profile to adult Web sites and other dicey online destinations. A new service called TwitBlock makes this task of separating spam from fan an interesting and fun – if not always accurate – exercise (hat tip to Mashable). TwitBlock uses OAuth, an open authentication protocol that allows users to approve an application to act on their behalf without sharing their password. More information on using OAuth is available here. The criteria by which TwitBlock rates the spamminess of a Twitter follower is explained here. TwitBlock is still in alpha mode, meaning it