Just discovered a new Firefox extension plugin today - ScribeFire (formerly performancing) which lets you create and edit blog posts direct from within the firefox interface. In fact this is my first post using it, so it's a bit of a 'test' post!
It's pretty cool as it supports a wide variety of blogging APIs and does a 'split' window mode.
This mode is quite cool as it allows you to have ScribeFire open at the bottom area of your window and the site you're browsing at the top - which makes it easier to get accurate context when writing. Nice
Anyway give it a go and let me know what you think about it.