A trailer for the RedBus Films launch It's all Gone Pete Tong will be available free to the first 100,000 3 customers to download the clip.
The 30-second spot and information about the film will be available from this week on 3's "Today on 3" service. It was placed on 3 as part of a wider campaign bought by Mediaedge:cia.
RedBus is the latest advertiser to explore 3G; earlier this month Peugeot used Vodafone's 3G service to launch its 1007 super-mini.
Gareth Jones, the chief operating officer of 3, said: "This is a very exciting development - advertisers have a new and targeted visual medium with which to reach consumers. We also know the profile of our customers, this means that ads or paid-for-content can be tailored and relevant."