Daniel if you google for natural flea remedies you will find a TON of sites. There is a type of stuff I used to use on the carpets so that our kids wouldn't be exposed to toxins in most commercial flea repellents. It's called diatomaceous earth though I can't for the life of me remember where we got it. If I remember correctly it dries out their environment (fleas LOVE liquid that's why they head for eye areas of pets) and naturally kills them off. When you vaccuum remember you have to tie off the vaccuum bag and get it out of the house right away or any determined adult fleas will crawl right back out and reinfest the area.
Remember to do your bedding and pillows in a VERY hot dryer to kill off anything and flip and treat your own mattress as fleas will be there if the cat has slept with there.
If you call any of the larger natural foods stores they may be able to give you more ideas or resources for natural methods of flea extermination.
~~Jo~~