Mobile advertising is not all talk. Along with its rumored "Gphone," Google has recently extended AdSense to the mobile platform. Its interest in buying wireless spectrum further demonstrates its interest in this space. Meanwhile, Yahoo! has leapt into the fray with various acquisitions and upgrades, including a partnership with Telefonica that doubles its mobile search reach. AOL purchased Third Screen Media. And even ad networks are entering the space and thereby easing advertiser entry. So mobile's hot-factor is real, but how are brands leveraging this medium to extend their message right now?

Three mobile marketing experts -- John Hadl of Brand in Hand, Jack Philbin of Vibes Media and Gene Keenan of Isobar Global -- relay examples of how they've used mobile to complement another medium and extend a brand's message.

Read on to see how CoverGirl leveraged a mix of TV, print and mobile to further its brand message; how a radio station in New York launched an iPhone promotion with SMS to boost listenership and how Reebok combined outdoor and texting to maximize customer "enablement."