I use NFP and we have been since my Mirena was removed in 2/07. So far it has been working for us ! I had wanted to give my body a break from all the hormones. We only use condoms during fertile times or we just abstain. I track my cycles at http://www.mymonthlycycles.com
and they notify me when I am fertile. I have them send me the reminder 2 days before and then I look at their calander and figure an extra 3 days after what they show, just to be safe :) You can also look into the Leah's Shield which is like the diaprham but it doesnt need to be fitted. I think you may need to use a spermicide with it also. There is a ntural spermicide that women who have irritation problems with nonoxnyl 9 use called Femprotect. However it doesnt seem to be available in the US.