Bollywood actor Aamir Khan on Saturday roamed around in Varanasi in disguise as he thought up an innovative way to promote his forthcoming film '3 Idiots'.

Earlier on Friday, the star cast of the film had disclosed that Khan would be on an adventure trip throughout the country for two weeks.

Khan has promised his fans a new look in every city and town that he visits during the next fortnight and the challenge for his fans would be to spot him before he unveils his new look everyday.

His close friends will constantly keep giving clues about his whereabouts to the fans. The first clue will be given by Master blaster Sachin Tendulkar.

Khan has described this as an 'Alternative Reality Game' (ARG) of Three Idiots, wherein fans would be able to locate and find him through a series of subtle clues about the city or town he is in and the get up he would be in - without outrightly giving away his whereabouts.

And announcement was made on television that whosoever would identify and find Khan in his disguise will be given free tickets for the movie and as a bonus Khan would spend New Year's night with the lucky winner and his family.

Khan spent entire day in Varanasi on Saturday and managed to stay unnoticed.

Khan roamed around the riverbanks and also took a boat as well as auto rickshaw ride in an attire of elderly Banarasi babu, wearing light colour sweater and dentures and chewed betel leaves.

Varanasi is also birthplace of Khan's mother. He visited tiliya nala, the locality his mom had spend her childhood in. He also visited Dasaswamedh Ghat where his mother used to go every evening for boat rides when they used to stay in Banaras.

'3 Idiots' is the celluloid adaptation of author Chetan Bhagat's best selling novel 'Five Point Someone'.

Directed by Rajkumar Hirani, the film essays the story of three friends whose dismal grade point averages at the Indian Institute of Technology influence their friendship, love life and career choices.

Sharman Joshi, Aamir Khan and R. Madhavan who are starring together in this film, were also co-stars in the critically acclaimed 'Rang De Basanti', which won several awards.

The film, set for release on December 25, has brought Khan and producer-director Vidhu Vinod Chopra together for the first time.

The film also stars actor Kareena Kapoor in the female lead.