Twitter crashes a lot, but not normally for very long.
From a business point of view, it can be a handy tool. If you're willing to offer expertise and guide people to useful information, 'followers' will start to value you. I have found some great resources there. I found this formun there! If you blog for a living, follow Brian Clark of copyblogger - he's writing is always spot on. He really 'gets' twitter.