Check your popularity with popuri.us
Here is a new, useful service – popuri.us. It gets information from several places – Alexa and Google; backlink numbers from the likes of Google, Live Search and Yahoo; bookmark numbers from del.icio.us; and subscriber numbers from Bloglines and displays it on one page. Sure this service is a good example of Web 2.0 technology. Have a look it and have fun 
[via Lifehacker]
You might be interested in SEO for Firefox extension: http://tools.seobook.com/firefox/seo-for-firefox.html
It does all that and more. You can enable/disable it with one click, configure what information to show, and if it should get the data on-load or on-request.
The best part of it is that it shows the information for search results on Google/Yahoo/MSN. Check the link for some screenshots.
Cool plug-in! Thanks for useful link, man!