I have been using Twitter for a littlewhile now. It is fast, very entertaining, and you can connect to and with friends, colleagues, business partners and like-minded people in your field.
A few days ago I spoke to a client of mine from a few years ago who wondered why his company was not using twitter for their own business since their RSS subscriber number was not that great (~150). The idea of his was to use twitter as a tool to show the more personal, more human side of the business, being able to interact with its customers and visitors, and engaging with similar companies, suppliers, even competitors. Well, that was the idea at least, and he asked me what I thought about that.