Old media could use an infusion of iPhone app ad dollars. USA Today and NPR Mobile are the latest news organizations to launch free iPhone apps. And since they’re free, you can bet that they’re hoping mobile marketers can help them revive nosediving ad revenues.

In order to stay afloat in the smartphone era, news companies know the importance of building a popular free iPhone app, and then loading it up with mobile advertising.

The two companies join tons of other news outlets in the App store, including The New York Times, BBC, Fox News, and a series of news sites built by Verve Wireless, including AP Mobile News Network, The New York Times Company’s Regional Media Group and McClatchy newspapers.

Newspapers are struggling as ad profits are down. Today, the New York Times said that both its print and online advertising revenue dropped 20.9 percent in November over a year ago. Internet ad revenue for its New Media Group decreased four percent in November.

Even so, New Media ad sales are a shining ray of hope. The Times said Internet businesses accounted for 12.1 percent of total revenue in November compared with 10.7 percent of total revenue in November 2007, reports The Washington Post.

USA Today’s app gives consumers access to the latest news, headlines, weather, photos and interactive polls. Consumers using an iPhone or iPod touch can access articles from News, Money, Sports, Life, Tech and Travel sections, and can share them through email, text message and Twitter, or save them to read at a later time.

The free NPR Mobile app allows users to browse and stream NPR programs, plus it includes an NPR station finder, reports Gizmodo.