there's wot extension, which can be downloaded from
http://kmext.sourceforge.net/macros/WOTratings.7z
enables viewing wot rating for links or current page
wot is reputation by users and should not be taken for granted as what they 'recommend' is true..in my opinion, it's a controversial extension and there has been several complaints by websites that wot people may give bad ratings not in a trustworthy way but more for personal issues. worth mentioning that one of the first wot founders was incriminated in a scam which caused a scandal..wot doesn't know if a website contains malware etc but i suppose it can give ratings on shopping websites where users may have had bad experience or delayed delivery etc..anyway it's a nanny extension made by housewives for housewives and it's only popular because people are brainwashed same reason a spying extension like noscript is popular.
site advisor is a spyware and virus scanner for websites(computer not people).. it can detect trojans or malware scripts embedded in a page