Very cool tool! If you find yourself editing HTML, or just having trouble fixing formatting problems in your blog posts, you have to get Mozilla and installl the pnhtoolbar.
It lets you do cool stuff like outline all of the block elements -- "why is that indented there?!", view cookies, disable style sheets, enable a different style sheet, etc.
Is this for Mac only, do can PC users play with it, too?
It works for any Mozilla, so it can be used on Mac, Windows, Linux, etc.
Ta! :o)