Site Checker

DingItsup will notify you when a site goes down and/or comes back up. It will send you your choice of email, text or twitter to alert you.
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Google Monitor

This free monitor allows you to track your position in Google for any number of keywords you choose. It records your best and current position. Supports multiple sites and keyword lists.
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Calculate the Value of your Website

This site gives you the value of a website by measuring a variety of statistics like incoming links, social bookmarks and traffic. Although these kind of tools would never be how a buyer would value a website they do give you an idea of how sites compare to each other in value.

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Meta Tag Editor

This web tool helps you create meta tags for your web pages including optional advanced tags like distribution, rating and revisit tags.
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SEO Data Finder

URLinfo gives you access to an enormous amount of info about a website via a tabbed panel of tools. It’s really an online interface that accesses dozens of useful online databases from one place.
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Click Heat Map

This free javascript will allow you to record clicks on your website and view hot or cold spots. It gives you a quick overview and graphic represenation of how people use your site in a way that dry stats don’t convey.
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SEO Report

Linkscape will analyze your site (or any site you give it) and let you know how it ranks in terms of links to the site.
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