thumbshots
Websnapr
Websnapr lets you capture screenshots of (almost) any web page. Allow your visitors to instantly visualize any web page before clicking. Increase site traffic, click-through rate and site stickiness. ...
ShrinkTheWeb
Free website screenshot thumbnail generator service for webmasters
Bluga.net WebThumb
Bluga.net WebThumb provides a white-label web service API for generating web thumbnails and full size snapshots of websites.
Thumbshots
Thumbshots are screenshots of web pages in thumbnail sizes. Integrating thumbshots in your website enables your users to instantly visualize any web page before navigating to the site.