Pauline Jakober spotted an interesting Google AdWords ad type with a subscribe form directly under the ad.
We know AdWords was testing something like this back in January 2010, as a AdWords Contact Form Extensions Beta but since then we have not seen much of it.
As you can see, the ad asks the user to enter their email address and name, and hit "submit" to send the information to the advertiser. The ad also contains a privacy information link.
The previous version had a pop down version, with a more detailed lead capture form. Here is an old picture of that:
Have you seen this out in the wild recently?
Forum discussion at Sphinn.