Mark Pack, former Lib Dem Geek-in-Chief, has written a series of articles for Total Politics magazine on the use by councils of new technologies. In this month's article, Mark argues the case for councils having blogs. He says that it should not be a means of communication solely for individual councillors, but that council officers should consider using a blog to communicate what the council is doing.
The key argument that Mark makes is that people come back and read blogs regularly because they know they will have something new to say. Regular websites, on the other hand, need to advertise when they have something new to say because people only go to them when they want information that they know is there.
Anyway, read the whole article.