I ran across this SEO firefox plug-in while surfing the web and I would like to share it with you. Installing this plug-in is very easy almost effortless and doesn’t need you to register or create an account for that matter like what other SEO plug-ins require when you want to use them. After installing it, within a click of your mouse you could access the following information instantly:

• * Yahoo Backlinks / Inlinks
• * Pages in Yahoo Index
• * Google Backlinks
• * Google Cache
• * Pages in Google index
• * Google Translate to English
• * Google Related
• * PageRank Check
• * Bing Backlinks
• * Pages in Bing Index
• * Alexa Overview
• * Alexa Backlinks
• * Mass Check – multiple sources at once
• * Check DMOZ Inclusion
• * Keyword Density
• * Page Load Speed & Size Check
• * Quarkbase Search
• * Compete Analytics
• * HTML Validator
• * Server Header Viewer
• * Wayback Machine
• * Check robots.txt
• * Whois Info

(download this useful and nice SEO Firefox Plugin):

With this tool you can check keyword density easily and you can see backlinks of your competitors and so much uses you can imagine that can help in your blog promotion. One drawback I encountered was the PageRank (PR) checker, sometimes the rank cannot be retrieved, but you can always install Google toolbar to have a precise PR check of the website you are viewing.