Google Preview is an add-on for the
Mozilla Firefox browser, which works to shows captures of a webpage in thumbnail, within a list of results obtained from a search performed in Google or Yahoo!
This lets you access a website preview immediately, without needing to enter the site. Once the program has installed, the thumbnails are shown automatically each time you do a search.
Google Preview is a completely free tool and takes up a tiny amount of disc space: just 20KB. You won´t even realize you´ve installed it.