I’m using a Firefox extention called Performancing for Firefox (PFF) to post to this blog. I love it so far — wysiwyg editor, easy to use and well integrated in the browser. As an adjunct to the very smooth built-in editor for WordPress 2.0 it makes it very easy to post. PFF works with most blog sites (e.g. blogger, moveabletype.com, wordpress.com and more) and most self hosting software (e.g. WordPress, MoveableType, etc.). Works with Firefox 1.5 and above.
