Marketing stunts: planes, trains & mobile homes

Yes, they're buying billboards  and online banner ads. But here's some of the other stunts broadcasters have up their sleeves for fall.

>> The real-life Greenzo: For "Crusoe," NBC is going to build a tree house in Grand Central Station and an actor is going to live in the house for a week playing Robinson Crusoe.

>> Prepare for promotional takeoff: CBS  is covering  rooftops near LAX with banners promoting "The Amazing Race" to fliers, plus will air previews of their fall comedies on American Airlines flights.  NBC counters they have previews for their fall shows running as in-flight entertainment on United Airlines. 

>>Pie Hole driver: ABC has mobile home restaurant promoting "Pushing Daisies." The RV, decked out to look like the show's bakery The Pie Hole, will stop in 10 major markets offering free slices. 

>> Double-dipping: The CW sent ice cream wrapped in "90210" pool-party posters to beach areas in three cities.