I ran across a site called SiteAdvisor recently that helps people know about a website's history of spyware/adware and spam. It is owned by McCafee. You can download a plugin for either Internet Explorer or Firefox that will place a color coded indicator for how safe the site is. Also you can click on the indicator and it will open a page that gives details on the site. It works with Google and Yahoo searches as well, and will place a color coded icon next to each item in the search list.
I highly recommend it. You can download the plugin at
www.siteadvisor.comJeff