In my search of being lazy and wanting to blog I stumbled upon ScribeFire which is a Firefox extension/add-on.
Features that I love:
I highly suggest it as if you use Firefox it’s just a simple add-on and doesn’t require installation of a separate application while providing good and simple blogging tools. Only downside is that there doesn’t seem to be much information of on the features it provides on the ScribeFire website.
Powered by ScribeFire.
Edit: My bad you can add new Categories. You can even edit posts if you press the right button (which I didn’t the first time :P)