Five years ago, telling a friend that you interact regularly with a verbose orange traffic cone might earn you a pitying hug and a quick trip to the sanatorium. But these days, your friend might respond that they trade barbs with Rick Santorum's sweater vest. Welcome to the age of novelty Twitter accounts, where animals, inanimate objects and other nonhuman entities speak their mind regularly: A pigeon with a foul mouth and a fouler demeanor. San Francisco's famous fog. Even the universe. On the social-media platform, users can express themselves creatively and get laughs by giving voice to those things that ca n't speak for themselves. Novelty nonhuman accounts have been a Twitter staple since Sockington, a Boston-area housecat, joined the service in March 2007 on his way to 1.4 million followers. But they 've been in the news again recently after one user created @olympicseat, a tongue-in-cheek response to the curiously vacant seats at Olympic venues in London. In the span of a few days, it has amassed more than 21,000 followers. Another Olympics-related feed celebrates the star-spangled towel that American gymnast Danell Leyva drapes over himself between events. It has more than 12,000 followers -- not bad, considering the average Twitter user has 126. Most of the people in this group of noteworthy Twitterers say their primary motivation for tweeting is to have fun. For