Google added a new option to the web search toolbelt: page previews. If you click on "Show options" and select "Page previews" after performing a search, Google will show a longer snippet and a thumbnail for each search result.
Google's thumbnails include a small part of the page, so they aren't always helpful. Another issue is that all the thumbnails from a search results pages are merged and the resulting image doesn't load instantly.
Example: search results for [maps].
7 hours ago