Can I calculate FFT without using floating point numbers?

I have 8 or 10 bits samples coming from an Analog Digital Converter. They are unsigned integers.

I want to perform FFTs using an 8 bit AVR on blocks of 128 to 1024 samples.

Question: Can I evaluate those FFTs without using floating point variables, just signed or unsigned integers, to speed up calculations?

FFT algorithm in C: http://www.codeproject.com/KB/re...