How time flies and things change in the span of just over two years when it comes to anything mobile, including mobile advertising. Millennial Media today released its 50th report tracking trends on its mobile ad network, and it shows some not-too-surprising growth in several key categories.

The first report, released back in March 2009, showed 33 percent of devices on the Millennial ad network used a touch screen as the input device. Today, the figure is 60 percent based on 2011 second-quarter data.

In the first report, only 3 percent of all campaigns drove consumers to an App Store or app download page; that percentage now stands at 23 percent. As for local market targeting, fewer than 2 percent of campaigns leveraged local market targeting in the first 2009 report; now that figure is up to 44 percent of all targeted audience campaigns.

Since Millennial Media’s first S.M.A.R.T. report was released, two mobile devices have managed to stay on its list of the top 20 phones accessing the Millennial network: the iPhone and the BlackBerry Curve. Besides nine smartphones, the 2009 list included 11 features phones, which don’t even appear on the 2011 smartphone-only list.