Feng-GUI is a very interesting site, that i spent a lot of time on it. It is a Heatmap service. but unlike others, Feng-GUI does not use anything like Mouse movement, click tracking, server logs, eye-tracking technology etc.. The ViewFinder algorithm creates a Saliency attention heatmap. They say :

The ViewFinder Heatmap service, is an artificial intelligence service which simulates human visual attention and creates an attention heatmap.

What can you find with ViewFinder heatmap ?

• Which areas of the page/image gets most of the attention?
• Which areas are being ignored?
• Hotspots – Highest points of attention.

It is purely based on the colors of a site. It might not be an useful site for many. But its really interesting. Here are a few heatmaps :