Chilkur Balaji Temple popularly known as Visa Balaji Temple or Visa God is an ancient Hindu temple of Lord Balaji on the banks of Osman Sagar Lake near Hyderabad, India.

Typically, an aspiring American visa-seeker visits the temple a few days before his visa interview at the US consulate. During the visit, the devotee goes through the usual rituals of prayer, including three circles of the inner temple, and makes a vow.

Then, they go off with their documents and dreams to convince the US consulate officer that they are worthy of receiving the visa. If they get their visa, they return to the temple, and fulfil their vow, which is to walk 108 times around the temple.

Also, this is not the only Visa God in country, others are

1. Khadia Temple in Ahmedabad, Gujarat
2. Hanuman Temple in Neb Sarai, Delhi
3. Perumal temple in Chennai

source: http://timesofindia.indiatimes.com/edit-page/Visa-Temple/articleshow/1469705.cms

http://en.wikipedia.org/wiki/Chilkur_Balaji_Temple