John Lynch from Arizona State has been developing a nice list of history of science blogs/blogs written by historians of science, which is very exciting because it’s a great resource and also because I’ve been meaning to do such a thing for ages and now I don’t have to.  The list is shortish, but there really aren’t that many specifically history of science blogs (and PH is obviously a public history blog first and foremost).   So go check out his list and propose other blogs in the comments.