Firefox Add-on: GooglePreview

Google Preview is a nice little add-on that inserts preview images (thumbnails) of web sites into the Google and Yahoo search results pages. The Google Preview thumbnail system currently consists of 8 dedicated servers and generates 7 TB of traffic per month. It ads a small icon to Firefox status bar to turn it on and off.

Homepage: https://addons.mozilla.org/en-US/firefox/reviews/display/189