Last Friday I reported that Google was testing mobile ads in Japan. I just noticed via RSS that Google issued a press release on this at https://www.google.com/press/annc/mobile_ads_jp.html. Google explains the ads as;
Similar to ads that display in search done on a PC, Google mobile ads are text based. Rather, than displaying on the side, however, mobile ads display on the top and bottom of the search result page. The user can jump to the advertiser’s mobile webpage by clicking the link provided or can make a call directly to the advertiser just by clicking the “call” link in the ad.
You can also view pictures of the ads in action at https://mobile.google.co.jp/mobile_ads.