How long will it take to become a US citizen after sending the N400 application?

I have been an alien resident for over 5 years, I have recently sent my N-400 application to become a US citizen, How long will the whole process take before I can get my citizenship?

I understand it depends on number of factors, lets assume my application was correct, no mistakes, all documents provided.

I was talking to a person last night, he told me, his took less then three months. Based on him, INS hired more people to catch up. Is that ture? I have always heard 6-9 months.

Any help will be appreciated. Any one else out there who recently became a citizen?