[sdiy] extreme pitch-shifting?

[gregory zifcak]

hi all,
i am wondering about the best way to pitch down rf signals into audio range. 
i'm not trying to demodulate, just listen to say, 2.4 GHz noise dropped to 
1kHz. is my best bet super fast digital sampling and then lowering the clock 
frequency? or is there some type of divide-down scheme i could use (i'm 
guessing most rf noise is not squarewaves)?
thanks for any suggestions.
new to rf,
greg