I added a number of links to my wiki today surrounding website reputation investigations. These are useful in helping with my job of security analysis. So, I thought I'd take a moment to quickly compile a list of all the most important links of that nature in one place, because even if you have no interest in network security, the information these resources can provide you are endlessly useful, even for home users.
First, I recommend even the most seasoned veterans use the Web Of Trust plug-ins:
Second, this site is useful for scanning both individual files and websites for malicious activity:
Finally, the list of links below is useful for the more technically inclined:
http://www.IPVoid.com & http://www.URLVoid.com
For more information on each of these you can search for them on my wiki @ http://www.Schvenn.net.