Saturdays meeting of Web Development SIG was full of info about using and managing web-based social networking tools to help promote your business. Marc Majers claims that at his job at the Cleveland Institute of Art he spends approximately two hours a day working managing his content.
What was most usefull to me (althought I have not yet tried them out) was the availability of three meta tools that allow you to manage all the resources from a central site.
More after I've had a chance to try them out, Mark seemed found of hellotext.com.
Twitter has now moved from a person-to-person contact tool to one that businesses use to publish updates to potential customers. The important thing to remember is, that unlike email with it's huge spam problem, anyone who abuses the people on their follow list will soon find that no one is listening. As a business owner you had better limit your tweets and really offer something of value when you post.
Maintianing consistant periodic contact is important, otherwise you will be de-listed from the networking sites. Two attendess also identified themselves at marketers and seemed to perk up most with regard to Twitter. I've recently started using a new Twitter client called blu myself, but Tweetdeck seems like it would be best for maintaining huge lists of subscribed accounts.
Like all marketing methods you have to experment to find what provides the best bang for the buck; or maybe it's just the best bang for the keystroke.