GooglePreview is a simple Firefox extension that makes Google and, despite the name, Yahoo! search results more informative, providing a thumbnail of the listed site so you can more easily determine if it’s what you are looking for.

Thumbnails are served directly by GooglePreview servers for quicker access, hosted by extension developer Edward Ackroyd. If not found, they are retrieved from Alexa.

According to Edward, GooglePreview also serves product images and affiliate links provided by Amazon for product searches as a way to cover server expenses but after trying several product searches I still have to see one of those. So however it is implemented it has been done in a very unobtrusive way.

You can quickly switch between regular and thumbnailed search results through a status bar icon which , fortunately can be removed as a GooglePreview option.

I must confess I was skeptical about how useful this extension could be but after giving it a try I found it very transparent and really helps to better discriminate search results while adding no noticeable delay.

You can get GooglePreview from Mozilla Add-ons.