I'm pretty sure it's a Firefox 2 feature, but it may be EoFF, I don't know. But I found it awesome. When posting on the net, like I am doing right now, it shows you all your spelling errors just like it does in Microsoft Word. This is really going to help me as I am pretty terrible at typing and I am always finding myself instantly editing a post to fix the typos.

How good are you at spelling and typing?