Just a few years ago, a "blog" was simply a typographical error. In 2004, blogs are the buzzword of the presidential campaign. Every major presidential candidate has a blog of his own; and the candidates are discussed and dismissed on the millions of blogs that exist in cyberspace. A blog -- short for web log-- is something of a cross between an online diary and cybermagazine. This Sunday, Minnesota Public Radio will host the first sustained blog conversation on network radio. Christopher Lydon is an NPR reporter, blogger and the host of "The Blogging of the President." He says blogs can help form new communities.