I agree with Chandrasekaran that we all need to play our part if we expect anything to change at all. Taking or giving bribes is only one aspect of corruption in a society. Similar to your experiences when you refuse to pay bribes, I have had numerous hurdles thrown my way since school days for sticking with the rulebook. Since my grandparents were influenced by Gandhian priciples, it was not acceptable in our family to get anything done by paying under the table. So we were constantly given the runaround by the govt employees. Even though I don't live in India anymore, I have remained very interested in uprooting this evil from our society.
Here's a link to a discussion on BBC website about corruption in Africa and people's suggestion on "How can we fight corruption?"
I'm sure some of the suggestions are universal and can be applied to the Indian context.
And here is 2005 Transparency International Corruption Perceptions Index, the annual survey by the Berlin-based organization Transparency International. The index defines corruption as the abuse of public office for private gain, and measures the degree to which corruption is perceived to exist among a country's public officials and politicians.
Iceland is 1 (least corrupt), India is 88, Sri Lanka 78, and Bangladesh is 158 (most corrupt).