How to Block any Website in Google Searches

We have excellent spam block control in Gmail but can we extend the same feature to the web to block sites that provides spam type of results in Google Searches? Yes, we have with the following two methods:

a.) With this method you can block any results with any browser, just go to this Google link http://www.google.com/reviews/t and enter the website you want to block and provide a reason why you are blocking the site. Once you enter this manually, then that website or websites are blocked in your Google Search results. There is however only a limit of up to 500 websites and you have to enter each one of them manually. 

b.) This method uses Google Chrome extension called "Personal Blocklist (by Google)". After you install this extension in Google Chrome browser, just click the extension button in the Toolbar to block any website you find providing spam results or trying to make you install unnecessary programs. Later if you accidentally block the sites, you can easily unblock with this extension. However, this is limited to Chrome browser, if you are using other browser, you may or may not have similar extensions like the Personal Blocklist extension.

The method "b" is simple and easy to use, plus it is one-click choice compared to method "a".


Do you use any other method to block websites from appearing in Google Search results?