Heres an interesting one - last week while coming back from Bangalore, i cudnt locate the Bangalore - Hazrat Nizamuddin Rajdhani Express at the Bangalore station. I asked someone and he said its on PF8. Went there, there was some Airtel train standing. I thought what could it be and asked a person whether Rajdhani would come there. He said, this train is the Rajdhani. Yes, the Airtel Rajdhani Express.
Now, other Rajdhani expresses soon would be taken over by the corporates. What an idea for building ur brand (am not too sure Airtel requires it though), anyways soon u wud have the Vodafone Chennai Rajdhani and Reliance Mumbai Rajdhani heard across the country. Once inside, there was a clear change that was visible. The door to the coach read "Welcome Onboard The Airtel Rajdhani". U have pamphlets of the offers available with Airtel in the train. And ads whereever possible in the coach.
The best part was the service. After every hour (its a 34.5 hour journey from Bangalore City to H. Nizamuddin), you get this guy with a slick uniform with Airtel written all over, who cleans the coach to the last dirt. The food is much better than what it used to be.
Railways wont be complaining as their coffins are getting filled up.Neither does Airtel. And for the passenger, its added features in the train at no extra cost. So a win-win situation for everyone.
A thought - How about giving the whole station to a company? Hows this to hear - Welcome to the Airtel New Delhi station???

Cheers