There are now three more sites that want to help you spend your consumer dollars wisely, but that don't actually review products themselves.
Retrevo is a useful "vertical search" engine for technology products. It does a very nice job of categorizing links. For example, in my search for "Nikon D50," it broke out its results into four categories: documentation, info from the manufacturer, reviews, and blog posts. Very handy. It's missing pricing data (and thus a big revenue stream), but it looks like it will be extremely useful if you're looking for anything about a product that's not buying-related--if you're still in the research phase or if you already have the product, for example. Also, it previews each result in a window, so you don't lose context during your search. I like it. (I like CNET.com more, of course.)
DigitalAdvisor is a reviews site that rates products based solely on user reviews from around the Web (people may find Wize's rating system more useful). The site has its own community reviewing products as well and recently launched a feature where users can ask each other for advice on particular products or categories. It is very nicely done, and a quick scan indicates that there's a knowledgeable and friendly audience on the site ready to help folks out.
TheFind is a shopping search engine. It goes beyond tech products and covers housewares, beauty products, clothing, and so on. The press materials claim that it scours the Web and extracts products and pricing, instead of relying on data feeds to populate its database. My quick test of the product was positive: Searching for some slacks I had recently purchased online, I found more outlets on TheFind than I had on Google--or at least the presentation of the results was clearer than Google's, so it seemed like more. TheFind also has a handy "save bar" where you can park your "finds" and compare them to each other. TheFind needs to keep an eye on Google, which earlier this year acquired consumer search company Dulance. So Froogle may not be dead just yet.
Consumer product search is a huge business, and these services are not the only ones in it, just the youngest. See my recent posts on ViewScore and Wize, and older coverage on Dulance. See also Become.com (and this video of it on PodTech).