Maybe 2-3 times a week - the kitchen. It depends on how many times I cook during that week. The rest of the house, once a week. I am not too concerned with cleaning. I would't live in a totally dirty house, but I cannot clean like a maniac. There are more important things in life.
Having asked this question, possibly out of guilt, I would only do mine once a week as I have a problem sweeping/vacuuming due to an accident.
Very interesting replies and I agree with Mihaela about there are more important things in life however if I am having visitors I will go around and sweep the dirty bits -I think without children it stays so much cleaner.