Unlisted adds a checkbox for 'Unlisted' to the node publishing options. Unlisted nodes are not access controlled, simply excluded from all Views listings.
The S-Shot Screenshots module uses the s-shot.ru service to fetch and display thumbnails of web pages.
The module is a view widget for the Link module. Simply go to the display management page and select the "Sshot thumbnail" format.
Same formatter works in Views as well. There is an additional option to choose the screenshot image size.