There is a lot of junk on Facebook, but the fan pages that make it worthwhile provide useful information on a quasi-frequent basis. It's just like subscribing to a mailing list. Too much and I start to ignore.

I don't have a page, but my prof'l association announces events through their fan page. There is a drawing professor at my uni who has a fan page and he posts sketches and writes about the drawing process. And then I have a friend whose company uses it for PR, talking about things in the news that affect the industry or if they've won an award for a project. Another friend is also starting up their company and is using the fan page to help announce/roll out new products.