Businesses using Twitter; there's something to this idea. Even Twitter itself realizes it, as it's expected to be a part of its own business model launching soon. In the meantime, other companies continue to jump into the ring. The lastest is American Express, which today unveiled Pulse , a Twitter stream focused on small businesses. Pulse, which is a part of American Express' Open Forum site, uses Twitter's API to display the public tweets from small business owners. This stream can also be broken up into different small business industries, such as auto dealers, cleaning services, restaurants, and many others.