I mainly made this webpage for myself as I'm learning about SEO - search engine optimization. I hope these tools are useful for you as well. Use at your own risk.
http://www.widexl.com/remote/search-engines/metatag-analyzer.html - meta tags
http://seobench.com/keyword-density-analyzer/
http://www.linkvendor.com/seo-tools/domains-from-ip.html - ip address / domain names (use cmd.exe, ping www.etc.com)
http://www.geobytes.com/IpLocator.htm - ip address geographic locator
http://www.copyscape.com/ - look for duplicate webpages
http://www.webconfs.com/similar-page-checker.php - compare two pages for similarity
http://www.webmaster-toolkit.com/search-engine-position-checker.shtml - position checker
http://www.webmaster-toolkit.com/class-c-checker.shtml - checks to see if two webpages are from the same Class C domain. Links to each other are given less weight in SEO terms than those in different class C IP Ranges (the last digits are wildcards .*)
http://www.google.com/trends - track the top cities to do a particular search and track volume of a search term on google.
http://www.vaughns-1-pagers.com/internet/google-ranking-factors.htm - some google ranking suggestions and advice.
http://www.webconfs.com/domain-age.php check out age of domain names.
http://www.word0.com/ listing of domain names (searchable too) - I don't think this works now.
http://www.seocentro.com/tools/search-engines/search-engine-saturation.html search engine saturation!
http://www.google.com/addurl/ - you have copy a word to make sure you are human
http://search.yahoo.com/info/submit.html - you have to sign in and have an account
http://search.msn.com/docs/submit.aspx - same as google
http://www.submitexpress.com/ - submits to a ton of search engines
02/16/2009 Last Updated