Looking to cut through the noise of millions of Twitter accounts? Twollo is designed to help Twitter users find a more targeted audience for their posts. There is a four-day free trial. After that, Twollo costs $5.99 a month for five key words; $9.99 a month for 10 keywords; $19.99 per month for 20 keywords, and $59.99 month for unlimited keywords. Annual subscriptions also are available for 5, 10 and 20 keywords.