I Love My SEO For Firefox Tool!
I use this tool almost everyday to help my online marketing / SEO. I can do an SEO Xray of any website and it lets me know the meta Title, Keywords, Description in seconds along with backlinks and the Who Is Information.
It also lets me turn it on every time I do a search on Google and a lot of extra things pop up under each search item to help me spy on the "Competition" I have a video showing how I use it here :
SEO For Firefox
Check it out and leave a comment of how you used it to help your online marketing...