The other great thins is that you can have multiple authors. I have written posts on a number of blogs on a semi-regular basis (must get another done for you soon Mike)
They are a good way of engaging with your clients (and suppliers) too
I created a blog on my website - I cant post urls yet but if you click the link in my signature and go to /resources/blog/ you can see that I created a blog that people can post comments on.
All you need is a little HTML knowledge. I decided that a blog would be more search engine friendly if it was just a normal web page.