I personally don't like the Snap Shots function when browsing the Internet. If you don't know what I'm talking about, they're those thumbnails that open in a pop-up window when moving your mouse over a link and display a preview of the website that link points to.
However, Snap Shots has now been implemented as a browser add-on and I do think its functionality can be useful when applied to searches. Once active, you can have an instant preview of all the results displayed after a search or all the posts listed in your online RSS reader, just to mention two examples of usage.
The plug-in includes some settings to customize its appearance and behavior. Sometimes, however, the image takes some time to load and I also miss a button to close the pop-up.