Dataopedia is a free web service which gives detailed information about any website. Dataopedia gets data from more than 50 sources and displays information about any website, such as traffic, online buzz, contact information, popularity in social bookmarking services (Stumble Upon, Digg, Delicious etc). In short Dataopedia gives complete information regarding any website.
It gives information in different tabs mainly traffic, multimedia, popularity, technical date and company information. In the traffic stats, it pulls out information from Alexa, Compete and Quantcast. It also shows which all countries are sending most of the traffic to a website.
In the social media popularity it displays information from Stumble upon, Digg, Delicious and Technorati. It also shows Twitter updates and Friendfeed with the domain name.
Apart from this, Dataopedia also gives information about domain registrant and domain details.
Nice tool.
Take a look also at http://www.sitonomy.com/?url=http://www.nirmaltv.com
I use http://www.estimix.com to calculate how much traffic a
website has. It seems to provide much better traffic information and competitive analysis for free.