You got several websites and you want to publish something with not much differences in all of them. Then Live Writer is the right tool for you. It lets you add different weblogs(from Wordpress, blogger, etc) and update them with couple of clicks. There are other solutions that can publish one post(exactly the same thing) on several weblogs, but they lack some WYSIWYG feature or they simply do not work with some of your weblogs(Wordpress in my case). I can recommend this MS tool for bloggers
Download Live Writer from here.