Google Gadget Ads, are customized "mini-sites" that run as ads on AdSense publisher websites. These ads are interactive, engaging, and will appeal to your users, simultaneously providing value to advertisers while getting visitors to stick around your site. The end result is that advertisers get more engaged users, users have a richer ad experience, and publishers opted in to image ads may see increased competition for their ad space.

Have you got any links of the articles describing that?

Yes... Its quiet interesting. Can you provide us with a URL for getting more details about that Ad-format?

This is where he/she lifted the information: http://adsense.blogspot.com/2007/09/...adget-ads.html