Google has added a new service for Adsense publishers, it is a referral service which allows publishers to recommend others to take up Adsense. For now, there are limited control over the look and feel for the referral ad, but it’s better then nothing right :)
By the way the ads supports multi languages too, interested to Sign up today !!!

Check your Adsense panel today.

Adsense Referral Tab

Steps to get it working

Pick out a referral button, and add it to your site. Users who sign up for AdSense through your referral button will learn about a great product, and you’ll have a new way to generate revenue - $100 when each user you refer first earns $100.

In addition, if you are a U.S. publisher, for Firefox with Google Toolbar referrals we will pay up to $1 per referral the first time a user installs Firefox. (We hope to make this available soon to international publishers.)

Google Adsense Referral Program Announcement