Web Site Ranking tools and Services

Below are some tools and services which help you in knowing the ranking of your web site. Note: The web site or web page ranking tools and service simply provide an idea how a site/page ranks, they do not help in increasing your web site rank.

Google PageRank
The famous Google PageRank comes with the Google Toolbar. The Google PageRank ranks a page on a scale of 0 to 10 where 10 is the highest. Google PageRank is based on several factors including number of in-bound links (other web pages that link to web page which is being ranked). Google.com carries a PageRank of 10 and so do Yahoo.com and MSN.com. Google PageRank is available on the Google Toolbar
Google Tool Bar.

GoogleRankings.com
Though, "Googlerankings.com is in no way affiliated, sponsored or in any way the property of or responsibility of Google.com.", it's still a great service. What I like about this site is that one can enter a set keywords and find out how a web site ranks in Google. However, I find that the ranking reported by the site are a few positions lower than the actual rank one sees when searching on Google.
The Googlerankings web site provides several other services - Determining the best keywords of your site

The Alexa service ranks your web site as a whole and is an indicator of people who came to your site, thus the popularity of your site.
Alexa.com