This excellant extension will let you post to your weblog from withing Firefox. It will split the screen in half, fo reasy viewing of your reference material. You can download it here. It supports Blogger.com, WordPress.com, Live Journal, TypePad.com, or any WordPress of Movable Type power blog.
I have been looking for something like this for a long time. For the longest time it seemed that Blogger got all of the good hacks, my favorite being Blogger for Word. The “Blog This” functionality of the Google Toolbar was also iresome to me, but no longer.
So, go download this extension, and Happy Blogging!
Update: There was a little bug where Performancing was inserting twelve spaces in front of the title and the first line of the post. That seems to have disappeared with the upgrade in the extension and my installation of WordPress 2.0.