There is a free add-on for Mozilla Firefox, Internet Explorer (6.0 and higher), Safari, and Google Chrome that is called Web of Trust, or WOT. WOT will warn you about dangerous and questionable sites. WOT bases a sites reputation on four components: trustworthiness, vendor reliability, privacy, and lastly, child safety.
The WOT website states: "WOT's unique tools are powered by our global community of millions of trustworthy users who have rated millions of websites based on their experiences. Our mission is to boost trust on the web by giving you an opportunity to share your own experiences of websites and the services they offer with others. By joining the WOT community you protect yourself and help others at the same time."
WOT works to protect you, whether you are doing a search engine inquiry, clicking a link sent to your web based email such as hotmail, yahoo mail, gmail and your ISP's webmail, or clicking a link from an advertiser on a social site.
Yes, even if you click on a link in Outlook, Outlook Express, or Thunderbird, WOT watches out for you. If you click on a link in Facebook for instance, and unknown to you, the site has a bad reputation, WOT saves you by throwing a warning up on your screen before you get to the site! You can even set it to block sites with a poor reputation.
WOT also says "While our primary source of knowledge are ratings and reviews from the WOT community, we also take advantage of nearly a hundred carefully chosen trusted sources, such as listings of phishing sites. This provides WOT with a fast, automated and reliable means of protecting our users from new, rapidly spreading online threats.
Sources have different weights based on their type and methodology, which means that one source can have a much larger effect on the reputation than another."
All in all, there is no 100% way of never going to a bad site, but with WOT available, you can avoid millions of sites that are bad for you, and for your computer. Millions of sites such as online shops that cheat customers, download sites that deliver malware, sites that send spam, and those with inappropriate content for kids, can be avoided by you by simply using WOT.