The New York Times (NYSE: NYT) has thrown down the gauntlet when it comes to ads on mobile apps, specifically its iPhone app. Over the weekend, it has started running roadblock interactive ads on its iPhone app, possibly the first such by a big publisher. See the attached image: that was an ad for, well, I forgot in the rush to take the screenshot, but assuming some water-related company. Dan over at SAI saw the first such run of an ad, for Visa. These interactive ads use a format by NYC-based mobile ad startup Medialets, which previously did the Dockers shakable ad earlier this year that got much press attention. Still early days on the ad, but since NYT’s one of the bigger media apps, would be interesting to get the data on interaction later down the line. The upside is this is as good a captive audience you can get in a digital medium, but risk of course is that these ads are pretty intrusive and risk irritating off some users.